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the lift off of a rocket is a(n) | (A) combined force (B) action force (C) reaction force (D) two of the above | C | A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gase... |
noble gases are the elements in group 17 of the periodic table. | (A) true (B) false | B | Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why... |
noble gases are nonreactive elements. | (A) true (B) false | A | Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL... |
noble gases include | (A) oxygen (B) nitrogen (C) argon (D) all of the above | C | Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why... |
all noble gases are | (A) odorless (B) colorless (C) radioactive (D) two of the above | D | Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL... |
noble gases have high boiling points. | (A) true (B) false | B | Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why... |
examples of nonmetals include | (A) carbon (B) phosphorus (C) sulfur (D) all of the above | D | Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have pr... |
there are fewer nonmetals than there are elements in any other class. | (A) true (B) false | B | Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right ... |
properties of nonmetals include | (A) high boiling point (B) ability to conduct heat (C) dull appearance (D) none of the above | C | As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pi... |
all nonmetals are very reactive. | (A) true (B) false | B | Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL... |
nonmetals are located on the right side of the periodic table. | (A) true (B) false | A | Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right ... |
most of the elements that make up the human body are nonmetals. | (A) true (B) false | A | An element is pure substance that cannot be broken down into other substances. Each element has a particular set of properties that, taken together, distinguish it from all other elements. Table 2.1 lists the major elements in the human body. As you can see, you consist mainly of the elements oxygen, carbon, and hydrog... |
the fuel used in nuclear power plants is | (A) krypton-92 (B) barium-141 (C) uranium-235 (D) none of the above | C | Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, o... |
what is missing from the following nuclear equation for the fissioning of uranium-235? kr + ba + ? + energy 235 141 | (A) 1 electron (B) 2 protons (C) 3 neutrons (D) 4 positrons | C | The Figure 1.2 shows how nuclear fission of uranium-235 occurs. It begins when a uranium nucleus gains a neutron. This can happen naturally when a free neutron strikes it, or it can occur deliberately when a neutron is crashed into it in a nuclear power plant. In either case, the nucleus of uranium-235 becomes extremel... |
in a nuclear power plant, the energy from nuclear reactions is used to boil water. | (A) true (B) false | A | Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, o... |
nuclear power plants do not produce air pollution. | (A) true (B) false | A | Nuclear power is clean. It does not pollute the air. However, the use of nuclear energy does create other environ- mental problems. Uranium must be mined (Figure 1.3). The process of splitting atoms creates radioactive waste, which remains dangerous for thousands or hundreds of thousands of years. As yet, there is no l... |
nuclear energy is a renewable energy resource. | (A) true (B) false | B | Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the... |
nuclear fusion occurs inside | (A) stars (B) planets (C) nuclear power plants (D) two of the above | A | Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. Thats because a great deal of energy is needed to overcome the force of repulsion between positively charged nuclei. The suns energy comes from fusion in its core, where temperature... |
fusion of two hydrogen nuclei produces | (A) a helium nucleus (B) a neutron (C) energy (D) all of the above | D | In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. |
nuclear fusion produces dangerous radioactive wastes. | (A) true (B) false | B | In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out so... |
the fuel needed for nuclear fusion is plentiful. | (A) true (B) false | A | Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pro... |
scientists are a long way from developing the technology needed to use nuclear fusion to produce electricity. | (A) true (B) false | A | Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pro... |
nitrogen bases in dna include | (A) adenine (B) uracil (C) ribose (D) two of the above | A | As you can see in Figure 5.1, each nucleotide includes a sugar, a phosphate, and a nitrogen base. The sugar in DNA is called deoxyribose. There are four different nitrogen bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). Chemical bonds between the bases hold the two strands of DNA together. Adenin... |
the backbone of a nucleic acid consists of alternating nitrogen bases. | (A) true (B) false | B | Nucleic acids consist of chains of small molecules called nucleotides. The structure of a nucleotide is shown in Figure 9.23. Each nucleotide contains a phosphate group (PO4 ), a sugar (C5 H8 O4 ) in DNA, and a nitrogen- containing base. (A base is a compound that is not neither acidic nor neutral.) There are four diff... |
functions of rna include | (A) copying the genetic code in DNA (B) carrying the genetic code to the cytoplasm (C) helping to make proteins based on the genetic code (D) all of the above | D | There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRN... |
dna is found only in the nucleus of cells. | (A) true (B) false | A | The nucleus is only found in eukaryotic cells. It contains most of the genetic material (the DNA) of the cell. The genetic material of the nucleus is like a set of instructions. These instructions tell the cell how to build molecules needed for the cell to function properly. That is, the DNA tells the cell how to build... |
optical instruments include | (A) microscopes (B) telescopes (C) cameras (D) all of the above | D | Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. |
optical instruments use lenses and mirrors to form images. | (A) true (B) false | A | Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. |
a compound microscope has | (A) two concave lenses (B) two convex lenses (C) one concave lens and one convex lens (D) none of the above | B | A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or m... |
the magnifications of all the lenses of a microscope are added together to yield the overall magnification. | (A) true (B) false | B | A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or m... |
the part of a camera that focuses light to form an image is the | (A) aperture (B) shutter (C) lens (D) film or sensor | C | A camera is an optical instrument that forms and records an image of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image digitally. Regardless of how the image is recorded, all cameras form images in the same basic way, as shown in the Figure 1.3. Light passe... |
the shape of the path in question 2 is | (A) round (B) circular (C) elliptical (D) none of the above | C | The motion of an object can be represented by a distance-time graph like the one in Figure 12.8. A distance-time graph shows how the distance from the starting point changes over time. The graph in Figure 12.8 represents a bike trip. The trip began at 7:30 AM (A) and ended at 12:30 PM (F). The rider traveled from the s... |
objects that have orbital motion include | (A) moons (B) satellites (C) asteroids (D) all of the above | D | Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies cons... |
it takes earth 24 hours to complete each orbit. | (A) true (B) false | B | Earth rotates on its axis once every 24 hours. This is the length of an Earth day. Earth orbits the Sun once every 365.24 days. This is the length of an Earth year. Earth has one large moon. This satellite orbits Earth once every 29.5 days. This moon is covered with craters, and also has large plains of lava. The Moon ... |
comets do not have orbital motion. | (A) true (B) false | B | Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This at... |
an object with orbital motion is constantly accelerating. | (A) true (B) false | A | Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies cons... |
which of the following properties characterizes bases? | (A) ability to react with metals (B) sour taste (C) bitter taste (D) two of the above | C | All bases share certain properties, including a bitter taste. (Warning: Never taste an unknown substance to see whether it is a base!) Bases also feel slippery. Think about how slippery soap feels. Thats because its a base. In addition, bases conduct electricity when dissolved in water because they consist of charged p... |
examples of acids include | (A) antacid tablets (B) vinegar (C) drain cleaner (D) all of the above | B | Acids have many important uses, especially in industry. For example, sulfuric acid is used to manufacture a variety of different products, including paper, paint, and detergent. Some other uses of acids are illustrated in Figure 10.7. |
the strength of an acid depends on how many hydrogen ions it produces when it dissolves in water. | (A) true (B) false | A | The strength of an acid depends on the concentration of hydrogen ions it produces when dissolved in water. A stronger acid produces a greater concentration of ions than a weaker acid. For example, when hydrogen chloride is added to water, all of it breaks down into H+ and Cl ions. Therefore, it is a strong acid. On the... |
an example of a weak base is sodium hydroxide. | (A) true (B) false | A | A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ |
acidity is the hydrogen ion concentration of a solution. | (A) true (B) false | A | The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions ... |
the reactants of photosynthesis include | (A) oxygen (B) chlorophyll (C) carbon dioxide (D) two of the above | A | What goes into the plant cell to start photosynthesis? The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the suns energy are necessary for photosynth... |
the products of photosynthesis include | (A) energy (B) carbon dioxide (C) water (D) oxygen | D | What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can b... |
photosynthesis changes light energy to chemical energy. | (A) true (B) false | A | Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxyge... |
photosynthesis takes place in a single chemical reaction. | (A) true (B) false | B | The overall chemical reaction for photosynthesis is 6 molecules of carbon dioxide (CO2 ) and 6 molecules of water (H2 O), with the addition of solar energy. This produces 1 molecule of glucose (C6 H12 O6 ) and 6 molecules of oxygen Stomata are special pores that allow gasses to enter and exit the leaf. (O2 ). Using che... |
organisms that undergo photosynthesis include | (A) plants (B) cyanobacteria (C) algae (D) all of the above | D | The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesi... |
a position-time graph shows how far an object has traveled at any given time since it started moving. | (A) true (B) false | A | The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given tim... |
a position-time graph shows the direction(s) the moving object has traveled relative to the starting position. | (A) true (B) false | A | The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given tim... |
the slope of a position-time graph can be used to find the moving objects | (A) velocity (B) position (C) acceleration (D) none of the above | A | In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The ste... |
the steeper the line on a position-time graph, the faster the objects motion is changing. | (A) true (B) false | A | In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The ste... |
what is the formula for calculating the average velocity of a moving object? | (A) average velocity = Δd/Δt (B) average velocity = Δt/Δd (C) average velocity = Δd x Δt (D) average velocity = Δd + Δt | A | Its easy to calculate the average velocity of a moving object from a position-time graph. Average velocity equals the change in position (represented by d) divided by the corresponding change in time (represented by t): velocity = d t For example, in Graph 2 in the Figure 1.2, the average velocity between 0 seconds and... |
a person or object may have stored energy because of its | (A) shape (B) position (C) velocity (D) two of the above | D | Did you ever see a scene like the one in Figure 17.4? In many parts of the world, trees lose their leaves in autumn. The leaves turn color and then fall from the trees to the ground. As the leaves are falling, they have kinetic energy. While they are still attached to the trees they also have energy, but its not becaus... |
an objects potential energy due to gravity depends on its | (A) weight (B) acceleration (C) height above the ground (D) two of the above | D | Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in ... |
a stretched rubber band has potential energy. | (A) true (B) false | A | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
food and batteries both contain potential energy. | (A) true (B) false | A | All of the examples of potential energy described above involve movement or the potential to move. The form of energy that involves movement is called mechanical energy. Other forms of energy also involve potential energy, including chemical energy and nuclear energy. Chemical energy is stored in the bonds between the ... |
compared with a less powerful device, a more powerful device can do | (A) more work in the same time (B) the same work in less time (C) less work in the same time (D) two of the above | D | Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules (J) and time is measured in seconds (s), so power is expressed in joules per second (J/s). This is the SI unit for power, also kno... |
if a microwave does 3000 j of work in 3 seconds, its power is | (A) 9000 W (B) 3300 W (C) 2700 W (D) 1000 W | D | Power can be calculated using the formula above if the amount of work and time are known. For example, assume that a microwave oven does 24,000 joules of work in 30 seconds. Then the power of the microwave is: 24000 J Power = Work Time = 30 s = 800 J/s, or 800 W Q: Another microwave oven does 5,000 joules of work in 5 ... |
if you know power and time, you can calculate work with the equation | (A) Work = Power x Time (B) Work = Power/Time (C) Work = Time/Power (D) none of the above | A | You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power Time For example, if you use a 1000-watt microwave oven for 20 seconds, how much work does it do? First express 1000 watts in J/s and then substitute this value for power the work equation: Work = 1000 J/s 20... |
to hit the bulls eye of a target, you have to aim an arrow | (A) at the center of the bull’s eye (B) above the bull’s eye (C) below the bull’s eye (D) to one side of the bull’s eye | B | When the archer releases the bowstring, the arrow will be flung forward toward the top of the target where shes aiming. But another force will also act on the arrow in a different direction. The other force is gravity, and it will pull the arrow down toward Earth. The two forces combined will cause the arrow to move in... |
examples of objects that have projectile motion include | (A) moons of planets (B) artificial satellites (C) paintballs (D) all of the above | C | You can probably think of other examples of projectile motion. One is shown in the Figure 1.3. The cannon shoots a ball straight ahead, giving it horizontal motion. At the same time, gravity pulls the ball down toward the ground. Q: How would you show the force of gravity on the cannon ball in the Figure 1.3? A: You wo... |
when an arrow is shot from a bow, forces acting on the arrow include the | (A) elastic force of the bow (B) force of gravity (C) force of friction (D) all of the above | D | When the archer releases the bowstring, the arrow will be flung forward toward the top of the target where shes aiming. But another force will also act on the arrow in a different direction. The other force is gravity, and it will pull the arrow down toward Earth. The two forces combined will cause the arrow to move in... |
a cannonball shot from a cannon has projectile motion. | (A) true (B) false | A | You can probably think of other examples of projectile motion. One is shown in the Figure 1.3. The cannon shoots a ball straight ahead, giving it horizontal motion. At the same time, gravity pulls the ball down toward the ground. Q: How would you show the force of gravity on the cannon ball in the Figure 1.3? A: You wo... |
an object with projectile motion constantly changes direction. | (A) true (B) false | A | Earths gravity also affects the acceleration of objects that start out moving horizontally, or parallel to the ground. Look at Figure 13.21. A cannon shoots a cannon ball straight ahead, giving the ball horizontal motion. At the same time, gravity pulls the ball down toward the ground. Both forces acting together cause... |
an example of an acid is hcl. | (A) true (B) false | A | An acid is an ionic compound that produces positive hydrogen ions (H+ ) when dissolved in water. An example is hydrogen chloride (HCl). When it dissolves in water, its hydrogen ions and negative chloride ions (Cl ) separate, forming hydrochloric acid. This can be represented by the equation: HCl H2 O + ! H + Cl |
all acids taste sour. | (A) true (B) false | A | You already know that a sour taste is one property of acids. (Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity because they consist of charged particles in solution. Acids also react with metals to produce hydrogen ga... |
when acids react with metals, they produce | (A) hydrogen gas (B) a salt (C) a base (D) two of the above | D | You already know that a sour taste is one property of acids. (Warning: Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current ... |
which statement about ph is true? | (A) A neutral solution has a pH of 0 (B) An acid has a pH greater than 7 (C) An acid has a pH less than 7 (D) A very weak acid has a pH close to 0 | C | The strength of acids and bases is measured on a scale called the pH scale, which is shown in the Figure 1.1. By definition, pH represents the acidity, or hydrogen ion (H+ ) concentration, of a solution. Pure water, which is neutral, has a pH of 7. With a higher the concentration of hydrogen ions, a solution is more ac... |
litmus paper is the only indicator of acids. | (A) true (B) false | B | Certain compounds, called indicators, change color when acids come into contact with them, so indicators can be used to detect acids. An example of an indicator is the compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of acid on a strip of blue litmus paper,... |
an example of a base is sodium hydroxide (naoh). | (A) true (B) false | A | A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ |
bases feel slippery to the touch. | (A) true (B) false | A | All bases share certain properties, including a bitter taste. (Never taste an unknown substance to see whether it is a base!) Did you ever taste unsweetened cocoa powder? It tastes bitter because it is a base. Bases also feel slippery. Think about how slippery soap feels. Soap is also a base. Like acids, bases conduct ... |
bases can react with metals. | (A) true (B) false | B | Acids are ionic compounds that produce positively charged hydrogen ions (H+ ) when dissolved in water. Acids taste sour and react with metals. Bases are ionic compounds that produce negatively charged hydroxide ions (OH ) when dissolved in water. Bases taste bitter and do not react with metals. Examples of acids are vi... |
bases turn red litmus paper blue. | (A) true (B) false | A | Bases change the color of certain compounds, and this property can be used to detect them. A common indicator of bases is red litmus paper. Bases turn red litmus paper blue. You can see an example in Figure 10.8. Red cabbage juice can detect bases as well as acids, as youll see by reviewing this video: MEDIA Click ima... |
bases are used to make | (A) soaps (B) cleaning products (C) concrete (D) all of the above | D | Bases are used for a variety of purposes. For example, soaps contain bases such as potassium hydroxide. Other uses of bases are pictured in Figure 10.9. |
the strongest bases have ph values close to | (A) 0 (B) 5 (C) 7 (D) 14 | D | The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH val... |
properties of electromagnetic waves include | (A) speed (B) frequency (C) wavelength (D) all of the above | D | Wavelength and frequency are defined in the same way for electromagnetic waves as they are for mechanical waves. Both properties are illustrated in Figure 21.5. Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction o... |
all electromagnetic waves travel at the same speed through space. | (A) true (B) false | A | All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromag... |
higher-frequency electromagnetic waves have less energy. | (A) true (B) false | B | Although all electromagnetic waves travel at the same speed across space, they may differ in their wavelengths, frequencies, and energy levels. Wavelength is the distance between corresponding points of adjacent waves (see the Figure 1.1). Wavelengths of electromagnetic waves range from longer than a soccer field to sh... |
some electromagnetic waves have wavelengths shorter than the diameter of an atom. | (A) true (B) false | A | As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequenc... |
all electromagnetic waves have frequencies of less than 1000 waves per second. | (A) true (B) false | B | Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. |
the highest-frequency electromagnetic waves | (A) include visible light (B) are harmful (C) have the longest wavelengths (D) two of the above | B | As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequenc... |
which equation shows the relationship of wave speed to wavelength and wave frequency? | (A) Speed = Wavelength x Frequency (B) Speed = Wavelength/Frequency (C) Speed = Frequency/Wavelength (D) none of the above | A | The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per seco... |
proteins are the most numerous and diverse biochemical compounds. | (A) true (B) false | A | Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. c... |
elements that make up proteins include | (A) nitrogen (B) phosphorus (C) hemoglobin (D) two of the above | A | Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. |
there are hundreds of different amino acids. | (A) true (B) false | B | Amino acids are the "building blocks" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the... |
what determines the shape of a protein? | (A) amino acid sequence of each chain (B) folding of each amino acid chain (C) number of amino acid chains (D) all of the above | D | Amino acids are the building blocks of proteins. There are 20 different amino acids. The structural formula of the simplest amino acid, called glycine, is shown in the Figure 1.1. Other amino acids have slightly different structures. A protein molecule is made from one or more long chains of amino acids, each linked to... |
examples of proteins by function include | (A) hormones (B) antibodies (C) enzymes (D) all of the above | D | Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. c... |
some proteins carry other materials in the blood. | (A) true (B) false | A | Hemoglobin is a compound in the class of compounds called proteins. Proteins are one of four classes of biochemi- cal compounds, which are compounds in living things. (The other three classes are carbohydrates, lipids, and nucleic acids.) Proteins contain carbon, hydrogen, oxygen, nitrogen, and sulfur. Protein molecule... |
protons are one of three main types of particles that make up atoms. | (A) true (B) false | A | A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which i... |
protons are found only in the atomic nucleus. | (A) true (B) false | A | A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which i... |
which of the following correctly describes a proton? | (A) It has an electrical charge of +2 (B) It has a mass of 1 mg (C) It has a diameter of 17 x 10-27 km (D) none of the above | D | A proton is a particle in the nucleus of an atom that has a positive electric charge. All protons are identical. It is the number of protons that gives atoms of different elements their unique properties. Atoms of each type of element have a characteristic number of protons. For example, each atom of carbon has six pro... |
in the sun, protons of hydrogen atoms | (A) fission to form energy (B) fuse to form helium nuclei (C) melt to form light (D) none of the above | B | A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which i... |
the atoms of different elements have | (A) different numbers of protons (B) different types of protons (C) the same number of protons (D) two of the above | A | All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their ... |
what are protons made of? | (A) gluons (B) neutrons (C) quarks (D) two of the above | D | Protons are made of fundamental particles called quarks and gluons. As you can see in the Figure 1.1, a proton contains three quarks (colored circles) and three streams of gluons (wavy white lines). Two of the quarks are called up quarks (u), and the third quark is called a down quark (d). The gluons carry the strong n... |
protons have less mass than electrons. | (A) true (B) false | B | Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number o... |
a flagpole pulley is a | (A) fixed pulley (B) moveable pulley (C) compound pulley (D) none of the above | A | Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure 1.3 how each of these m... |
the ideal mechanical advantage of a pulley is equal to the number of rope segments pulling up on the load. | (A) true (B) false | A | The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat ... |
a moveable pulley changes the direction of the input force. | (A) true (B) false | B | Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure 1.3 how each of these m... |
a zip-line pulley is a moveable pulley. | (A) true (B) false | A | Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulle... |
which type(s) of pulley can have a mechanical advantage greater than 2? | (A) fixed pulley (B) moveable pulley (C) compound pulley (D) two of the above | C | The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat ... |
all pulleys increase the force applied to the pulley. | (A) true (B) false | B | The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat ... |
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