instruction stringlengths 5 342 | input stringlengths 18 558 | output stringclasses 7
values | context stringlengths 31 6.57k |
|---|---|---|---|
Hemoglobin is a protein that fights infections in the blood. | (A) true (B) false | B | 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... |
The most abundant biochemical compound is cellulose. | (A) true (B) false | A | Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably ... |
Hemoglobin transports oxygen through the blood. | (A) true (B) false | A | Red blood cells (RBCs) are flattened, disk-shaped cells that carry oxygen. They are the most common blood cell in the blood. There are about 4 to 6 million RBCs per cubic millimeter of blood. Each RBC has about 200 million molecules of hemoglobin. Hemoglobin is the protein that carries oxygen. Hemoglobin also gives the... |
Muscle tissues are composed mainly of fatty acids. | (A) true (B) false | B | Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils.... |
Organisms use lipids mainly to store energy. | (A) true (B) false | A | Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. |
There are two main types of nucleic acids. | (A) true (B) false | A | Nucleic acids are biochemical molecules that contain oxygen, nitrogen, and phosphorus in addition to carbon and hydrogen. There are two main types of nucleic acids. They are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). |
long carbon chains found in lipids | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | F | Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, ... |
class of biochemical compounds that includes oils | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | B | Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. |
general name given to biochemical polymers | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | E | You can see from Table 2.1 that all biochemical compounds contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Most biochem... |
class of biochemical compounds that includes DNA | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | D | Nucleic acids are one of four classes of biochemical compounds. (The other three classes are carbohydrates, proteins, and lipids.) Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus. Q: ... |
building blocks of proteins | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | G | Proteins are molecules that have many different functions in living things. All proteins are made of monomers called amino acids ( Figure 1.2) that connect together like beads on a necklace ( Figure 1.3). There are only 20 common amino acids needed to build proteins. These amino acids form in thousands of different com... |
class of biochemical compounds that includes cellulose | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | A | Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen o... |
class of biochemical compounds that includes enzymes | (A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids | C | Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen o... |
Which of the following is one of the four main classes of biochemical compounds? | (A) sugars (B) starches (C) cellulose (D) carbohydrates | D | Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen o... |
All biochemical compounds include carbon, hydrogen, and | (A) sulfur (B) oxygen (C) nitrogen (D) phosphorus | B | A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, sma... |
Organisms use carbohydrates mainly for | (A) energy (B) cell membranes (C) hormones (D) antibodies | A | Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. |
The function of a given protein depends on its | (A) overall shape (B) sequence of amino acids (C) number of amino acid chains (D) all of the above | D | Proteins are biochemical compounds that consist of one or more chains of small molecules called amino acids. Amino acids are the monomers of proteins. There are only about 20 different amino acids. The sequence of amino acids in chains and the number of chains in a protein determine the proteins shape. Shapes may be ve... |
Which statement about saturated fatty acids is true? | (A) They have only single bonds between carbon atoms (B) They are used by plants to store energy (C) They make up lipids known as oils (D) They are always in the liquid state | A | Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, ... |
Nitrogen bases found in both DNA and RNA include | (A) glycine (B) adenine (C) thymine (D) uracil | B | 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... |
Which of the following is a function of RNA? | (A) fighting infections (B) reading the genetic code (C) carrying substances in the blood (D) all of the above | B | 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... |
Reactants in cellular respiration include | (A) oxygen (B) water (C) carbon dioxide (D) two of the above | A | What goes into the cell? Oxygen and glucose are both reactants of cellular respiration. Oxygen enters the body when an organism breathes. Glucose enters the body when an organism eats. |
All organisms make food by photosynthesis. | (A) true (B) false | B | 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... |
The synthesis of glucose requires carbon dioxide. | (A) true (B) false | A | What is the source of glucose for living things? It is made by plants and certain other organisms. The process in which glucose is made using energy in light is photosynthesis. This process requires carbon dioxide and water. It produces oxygen in addition to glucose. Photosynthesis consists of many chemical reactions. ... |
The human enzyme named pepsin catalyzes the digestion of | (A) nucleic acids (B) fatty acids (C) proteins (D) sugars | C | More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. Two examples are amylase and pepsin. Both are described in the Figure 1.2. |
Insect-catching plants such as pitcher plants obtain glucose from insects. | (A) true (B) false | B | Carnivorous plants are plants that get some or most of their nutrients (but not energy or carbon compounds) from other organisms. They trap and digest insects or other small animals or protozoa. However, they still need sunlight in order to make food by photosynthesis. Carnivorous plants have adapted to grow in places ... |
The compound that cells break down to release energy is | (A) chlorophyll (B) carbon dioxide (C) water (D) glucose | D | The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. ... |
Energy for photosynthesis comes from | (A) water (B) soil (C) light (D) chemicals | C | Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. |
Chemical reactions provide living cells with energy. | (A) true (B) false | A | Organic molecules must also carry out the chemical work of cells; that is, their metabolism. Chemical reactions in a living organism allow that organism to live in its environment, grow, and reproduce. Metabolism gets energy from other sources and creates structures needed in cells. The chemical reactions occur in a se... |
Photosynthesis is an exothermic, or energy-releasing, process. | (A) true (B) false | B | One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6... |
Which equation correctly represents photosynthesis? | (A) C6 H12 O6 + 6O2 + energy 6CO2 + 6H2 O (B) 6CO2 + 6O2 + energy C6 H12 O6 + 6H2 O (C) C6 H12 O6 + 6CO2 + energy 6O2 + 6H2 O (D) 6CO2 + 6H2 O + energy C6 H12 O6 + 6O2 | D | 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... |
The overall chemical reaction for photosynthesis is represented by the equation: C6 H12 O6 + 6O2 6CO2 | (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... |
Products of cellular respiration include many small, energy-storing molecules. | (A) true (B) false | A | The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. ... |
Cellular respiration takes place only in organisms that cannot make their own food. | (A) true (B) false | B | Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes calle... |
The process of cellular respiration requires carbon dioxide. | (A) true (B) false | B | Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respira... |
One of the products of cellular respiration is oxygen. | (A) true (B) false | B | What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be con... |
All living things need energy just to stay alive. | (A) true (B) false | A | All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ec... |
Cellular respiration is an endothermic, or energy-absorbing, process. | (A) true (B) false | B | Cellular respiration is the process in which the cells of living things break down glucose with oxygen to produce carbon dioxide, water, and energy. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + Heat and Chemical Energy Cellular respiration releases some of the energy in gl... |
Only plants can carry out photosynthesis. | (A) true (B) false | B | By the time the earliest plants evolved, animals were already the dominant living things in the water. Plants were also limited to the upper layer of water. Only near the top of the water column is there enough sunlight for photosynthesis. So plants never became dominant aquatic organisms. |
Cellular respiration occurs in all living cells | (A) true (B) false | A | Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes calle... |
One of the products of cellular respiration is oxygen. | (A) true (B) false | B | What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be con... |
process in which cells break down glucose and release energy | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | D | Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requi... |
any chemical reaction that takes place in living things | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | B | Chemical reactions that take place inside living things are called biochemical reactions (bio- means life). Its not just for energy that living things depend on biochemical reactions. Every function and structure of a living organism depends on thousands of biochemical reactions taking place in each cell. The sum of al... |
protein that speeds up biochemical reactions | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | G | Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so t... |
byproduct of photosynthesis | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | C | 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... |
compound that cells use for energy | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | E | Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in ... |
pigment that captures light energy | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | F | Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is chlorophyll, which is found in plants. This dark green pigment absorbs all but green wavelengths of visible ... |
process in which certain organisms make glucose | (A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme | A | Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs ("self feeders"). All other living things obtain glucose by eating autotrophs (or organisms that ea... |
All living things need | (A) carbon dioxide (B) sunlight (C) energy (D) two of the above | C | All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ec... |
Reactants in photosynthesis include | (A) chlorophyll (B) oxygen (C) glucose (D) water | D | 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... |
Types of organisms that make their own glucose include | (A) algae (B) plants (C) cyanobacteria (D) all of the above | D | Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs ("self feeders"). All other living things obtain glucose by eating autotrophs (or organisms that ea... |
All organisms that undergo photosynthesis contain | (A) pepsin (B) amylase (C) chlorophyll (D) two of the above | C | 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... |
Cellular respiration releases some energy in the form of | (A) heat (B) light (C) motion (D) electricity | A | Cellular respiration is the process in which the cells of living things break down glucose with oxygen to produce carbon dioxide, water, and energy. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + Heat and Chemical Energy Cellular respiration releases some of the energy in gl... |
Amylase catalyzes the breakdown of | (A) lipids (B) proteins (C) nucleic acids (D) complex carbohydrates | D | Chemical reactions constantly occur inside living things. Many of these reactions require catalysts so they will occur quickly enough to support life. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take many years wit... |
acceleration always refers to a(n) | (A) increase in speed (B) change in speed (C) change in direction (D) change in velocity | D | Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase... |
acceleration is a vector. | (A) true (B) false | A | Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors.... |
a change in direction without a change in speed is called velocity. | (A) true (B) false | B | You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in ... |
acceleration can never be negative. | (A) true (B) false | B | Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase... |
a heavier object always falls to the ground more quickly than a lighter object. | (A) true (B) false | B | What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at the same t... |
what is the velocity of an object that has been falling freely in a vacuum for 4 seconds? | (A) 98 m/s (B) 101 m/s (C) 196 m/s (D) 392 m/s | D | Gravity is a force that pulls objects down toward the ground. When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velo... |
objects fall toward earth at a constant rate of speed. | (A) true (B) false | B | When gravity pulls objects toward the ground, it causes them to accelerate. Acceleration due to gravity equals 9.8 m/s2 . In other words, the velocity at which an object falls toward Earth increases each second by 9.8 m/s. Therefore, after 1 second, an object is falling at a velocity of 9.8 m/s. After 2 seconds, it is ... |
an object will experience more air resistance when it falls if it has greater | (A) mass (B) weight (C) gravity (D) surface area | D | What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at the same t... |
objects with different masses have the same gravitational force acting on them. | (A) true (B) false | B | Gravity has traditionally been defined as a force of attraction between two masses. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. The effect of gravity is that objects exert a pull on other objects. Unlike friction, which acts only between objects ... |
if a measurement is precise, it must also be accurate. | (A) true (B) false | B | Measurements should be both accurate and precise. Accuracy is how close a measurement is to the true value. For example, 66 mL is a fairly accurate measure- ment of the liquid in Figure 2.6. Precision is how exact a measurement is. A measurement of 65.5 mL is more precise than a measurement of 66 mL. But in Figure 2.6,... |
only accurate measurements are precise. | (A) true (B) false | B | The accuracy of a measurement is how close the measurement is to the true value. If you were to hit four different golf balls toward an over-sized hole, all of them might land in the hole. These shots would all be accurate because they all landed in the hole. This is illustrated in the sketch below. |
which set of measurements best represents precision if the true value is 6.80 kg? | (A) 680 kg (B) 670 kg (C) and 690 kg (D) b 675 kg (E) 680 kg (F) and 685 kg (G) c 580 kg (H) 680 kg (I) and 780 kg (J) d 610 kg (K) 599 kg (L) and 611 kg | D | Measurements should be both accurate and precise. Accuracy is how close a measurement is to the true value. For example, 66 mL is a fairly accurate measure- ment of the liquid in Figure 2.6. Precision is how exact a measurement is. A measurement of 65.5 mL is more precise than a measurement of 66 mL. But in Figure 2.6,... |
which set of measurements best represents accuracy if the true value is 6.80 kg? | (A) 680 kg (B) 670 kg (C) and 690 kg (D) b 675 kg (E) 680 kg (F) and 685 kg (G) c 580 kg (H) 680 kg (I) and 780 kg (J) d 610 kg (K) 599 kg (L) and 611 kg | B | The accuracy of a measurement is how close the measurement is to the true value. If you were to hit four different golf balls toward an over-sized hole, all of them might land in the hole. These shots would all be accurate because they all landed in the hole. This is illustrated in the sketch below. |
pure water is an example of a neutral substance. | (A) true (B) false | A | Water (H2 O) is an example of a chemical compound. Water molecules always consist of two atoms of hydrogen and one atom of oxygen. Like water, all other chemical compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. |
when an acid dissolves in water, it produces | (A) positive hydrogen ions (B) negative nonmetal ions (C) negative metal ions (D) two of the above | D | An acid is a compound that produces positive hydrogen ions (H+ ) and negative nonmetal ions when it dissolves in water. (Ions are atoms that have become charged by losing or gaining electrons.) Hydrochloric acid (HCl) is an example of an acid. When it dissolves in water, it produces positive hydrogen ions and negative ... |
when a base dissolves in water, it produces | (A) positive hydroxide ions (B) positive metal ions (C) negative nonmetal ions (D) two of the above | B | 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+ |
the reaction of hydrochloric acid and calcium carbonate produces | (A) water (B) calcium chloride (C) carbon dioxide (D) all of the above | D | When an acid and a base react, the reaction is called a neutralization reaction. Thats because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. Lets see how a neutralization reaction produces both water and a salt, using as an example ... |
only endothermic reactions require activation energy. | (A) true (B) false | B | Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energ... |
the activation energy needed to start combustion in a car engine comes from | (A) the gasoline (B) a spark plug (C) a piston (D) the key | B | Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion o... |
a chemical reaction will not occur unless reactants are moving. | (A) true (B) false | A | Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion o... |
all chemical reactions need a constant input of energy to continue. | (A) true (B) false | B | Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energ... |
exothermic reactions always need less activation energy than endothermic reactions. | (A) true (B) false | B | Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energ... |
all of the following are alkaline earth metals except | (A) barium (B) sodium (C) calcium (D) magnesium | B | The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. T... |
properties of alkaline earth metals include | (A) gray or silver color (B) low density (C) softness (D) all of the above | D | The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. T... |
all alkaline earth metals have three valence electrons. | (A) true (B) false | B | All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metal... |
alkaline earth metals are the most reactive metals. | (A) true (B) false | B | The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. T... |
alkaline earth metals never exist as pure substances in nature. | (A) true (B) false | A | The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. T... |
diets that are too low in calcium may lead to | (A) rickets (B) osteoporosis (C) bone fractures (D) all of the above | D | Osteoporosis is a disease in which the bones become porous and weak because they do not contain enough calcium. The graph in Figure 16.14 shows how the mass of calcium in bone peaks around age 30 and declines after that, especially in women. Maximizing the calcium in your bones while youre young will reduce your risk o... |
alloys consist only of metallic elements. | (A) true (B) false | B | An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Se... |
most metal objects are made of alloys rather than pure metals. | (A) true (B) false | A | Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is use... |
which of the following is not an alloy? | (A) chromium (B) bronze (C) brass (D) steel | A | Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is use... |
the alloy called stainless steel consists of | (A) iron (B) carbon (C) nickel (D) all of the above | D | Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is use... |
the first alloy ever made was | (A) sterling silver (B) steel (C) brass (D) bronze | D | Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is use... |
brass is an alloy that is used for doorknobs and plumbing fixtures. | (A) true (B) false | A | Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is use... |
an alpha particle is a | (A) packet of energy (B) single electron (C) helium nucleus (D) none of the above | C | Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure 1.1 shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus. Losing the protons and neutrons makes the n... |
what does the following nuclear symbol represent? | (A) alpha particle (B) helium atom (C) helium ion (D) none of the above | A | Radioactive nuclei and particles are represented by nuclear symbols.. For example, a beta-minus particle (electron) is represented by the symbol 01 e. The subscript -1 represents the particles charge, and the superscript 0 shows that the particle has virtually no mass (no protons or neutrons). Another example is the ra... |
in the nuclear symbol 6 c, the superscript represents the | (A) atomic number (B) mass number (C) valence number (D) group number | B | Radioactive nuclei and particles are represented by nuclear symbols that indicate their numbers of protons and neutrons. For example, an alpha particle (helium nucleus) is represented by the symbol 42 He, where He is the chemical symbol for helium, the subscript 2 is the number of protons, and the superscript 4 is the ... |
in the following nuclear equation for alpha decay, what is the missing subscript that will balance the equation? th + 42 he + energy 238 234 | (A) 94 (B) 92 (C) 90 (D) 88 | C | Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equation... |
an alpha particle consists of one proton and one neutron. | (A) true (B) false | B | Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure 1.1 shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus. Losing the protons and neutrons makes the n... |
alpha decay is the least dangerous type of radioactive decay. | (A) true (B) false | A | All types of radioactive decay pose risks to living things, but alpha decay is the least dangerous. Thats because alpha particles are relatively heavy, so they can travel only a few centimeters through the air. They also are not very penetrating. For example, they cant pass through a sheet of paper or thin layer of clo... |
archimedes was a greek mathematician who lived more than 2000 years ago. | (A) true (B) false | A | Some of the earliest scientific research on fluids was conducted by a French mathematician and physicist named Blaise Pascal (16231662). Pascal was a brilliant thinker. While still a teen, he derived an important theorem in mathematics and also invented a mechanical calculator. One of Pascals contributions to our under... |
archimedes determined that the volume of water displaced by an object placed in the water is equal to the objects | (A) weight (B) volume (C) mass (D) density | B | Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displace... |
a bigger object displaces less water than a smaller object. | (A) true (B) false | B | Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displace... |
according to archimedes law, the buoyant force acting on an object equals the | (A) weight of the object (B) weight of the displaced fluid (C) volume of the object (D) volume of the displaced fluid | B | Objects such as ships may float in a fluid like water because of buoyant force. This is an upward force that a fluid exerts on any object that is placed in it. Archimedes discovered that the buoyant force acting on an object equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Arc... |
archimedes law explains why some very heavy objects can float on water. | (A) true (B) false | A | Archimedes law explains why some objects float in fluids even though they are very heavy. It all depends on how much fluid they displace. The cruise ship pictured in the opening image is extremely heavy, yet it stays afloat. If a steel ball with the same weight as the ship were placed in water, it would sink to the bot... |
how does an incandescent light bulb produce visible light? | (A) The bulb’s filament gets so hot that it glows (B) Gas inside the bulb gives off visible light (C) Electricity excites neon electrons in the bulb (D) two of the above | A | An incandescent light bulb like the one pictured in the Figure 1.1 produces visible light by incandescence. Incan- descence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot... |
in a fluorescent light bulb, mercury gas gives off visible light. | (A) true (B) false | B | A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure 1.2 contains mercury gas that gives off ultraviolet light when electri... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.