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an external combustion engine burns fuel to heat air. | (A) true (B) false | B | An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other d... |
external combustion engines are no longer in use today. | (A) true (B) false | B | An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other d... |
all materials respond to magnetic force. | (A) true (B) false | B | Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. No doubt youve handled refrigerator magnets like the ones in Figure 24.5. You probably know first-hand that they stick to a metal refrigerator but not to surfaces such as wooden doors and glass windows. Wood and glass arent attra... |
nonmagnetic materials include | (A) wood (B) glass (C) plastic (D) all of the above | D | Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the mate... |
magnetism is due to the movement of electrons within atoms. | (A) true (B) false | A | Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the mate... |
all of the following materials can be magnetized except | (A) iron (B) carbon (C) cobalt (D) nickel | B | Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materia... |
if you stroke an iron nail with a bar magnet, the nail will become a temporary magnet. | (A) true (B) false | B | Materials that have been magnetized may become temporary or permanent magnets. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains line up. As a result, the paper clips will stick to the magnet and also to each other (see the Figure 1... |
a permanent magnet can be demagnetized by | (A) dropping it (B) heating it (C) cooling it (D) two of the above | D | Materials that have been magnetized may become temporary or permanent magnets. An example of each type of magnet is described below. Both are demonstrated in Figure 24.7. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains align. As a... |
fundamental forces of the universe include | (A) gravity (B) friction (C) electromagnetic force (D) two of the above | D | The interactions of matter particles are subject to four fundamental forces: gravity, electromagnetic force, weak nuclear force, and strong nuclear force. All of these forces are thought to be transmitted by bosons, the force- carrying fundamental particles. The different types of bosons and the forces they carry are s... |
the main forces that affect the motion of everyday objects include | (A) gravity (B) friction (C) applied force (D) all of the above | D | Force is defined as a push or pull acting on an object. There are several fundamental forces in the universe, including the force of gravity, electromagnetic force, and weak and strong nuclear forces. When it comes to the motion of everyday objects, however, the forces of interest include mainly gravity, friction, and ... |
only some changes in speed or direction are caused by forces. | (A) true (B) false | B | Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the ob... |
the force required to change an objects motion depends on the objects mass. | (A) true (B) false | A | A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The s... |
force is a vector. | (A) true (B) false | A | Force is a vector because it has both size and direction. For example, the girl in Figure 13.1 is pushing the swing away from herself. Thats the direction of the force. She can give the swing a strong push or a weak push. Thats the size, or strength, of the force. Like other vectors, forces can be represented with arro... |
energy can change from one form to another. | (A) true (B) false | A | Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, ... |
the energy of moving electrons is called chemical energy. | (A) true (B) false | B | 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 ... |
electromagnetic energy includes | (A) light energy (B) sound energy (C) heat energy (D) two of the above | A | Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). |
energy that travels in waves through matter is | (A) nuclear energy (B) electrical energy (C) sound energy (D) two of the above | C | The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the med... |
the pitch of sound depends on the amplitude of sound waves. | (A) true (B) false | B | How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds... |
compared to a higher-pitched sound, a lower-pitched sound always has a | (A) shorter wavelength (B) smaller amplitude (C) lower frequency (D) two of the above | C | How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds... |
the frequency of sound waves is measured in | (A) meters (B) meters/second (C) hertz (D) none of the above | C | The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit f... |
dogs can hear sounds that are too high in pitch for humans to hear. | (A) true (B) false | A | The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. So... |
what is the highest-frequency sound that humans normally can hear? | (A) 20 Hz (B) 200 Hz (C) 2000 Hz (D) 20 (E) 000 Hz | D | The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. So... |
only rough surfaces have friction between them. | (A) true (B) false | B | Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier ob... |
factors that affect friction between two surface include the | (A) smoothness of the two surfaces (B) area of the two surfaces (C) amount of force pressing the two surfaces together (D) all of the above | D | Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure 13.8. The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very... |
heavier objects have less friction with the floor than lighter objects. | (A) true (B) false | B | Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier ob... |
the blades of your skates slide more easily over ice than do the soles of your shoes because the skate blades | (A) exert less force on the ice (B) make you weigh less on the ice (C) have less surface area in contact with the ice (D) none of the above | C | Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes m... |
friction produces heat because it causes molecules to move faster and have more energy. | (A) true (B) false | A | You know that friction produces heat. Thats why rubbing your hands together makes them warmer. But do you know why the rubbing produces heat? Friction causes the molecules on rubbing surfaces to move faster, so they have more heat energy. Heat from friction can be useful. It not only warms your hands. It also lets you ... |
engine oil reduces friction between the moving parts in a car engine by | (A) cooling the engine (B) reducing the forces on the parts (C) making the parts slippery (D) two of the above | C | Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than s... |
which fundamental particle was discovered first? | (A) gluon (B) photon (C) quark (D) electron | D | Scientists have long wanted to find the most basic building blocks of the universe. They asked, what are the fundamental particles of matter that cannot be subdivided into smaller, simpler particles, and what holds these particles together? The quest for fundamental particles began thousands of years ago. Scientists th... |
fundamental particles that make up protons and neutrons are known as | (A) bosons (B) leptons (C) quarks (D) none of the above | C | 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... |
scientists think that leptons and quarks are held together by neutrinos. | (A) true (B) false | B | Based on their knowledge of subatomic particles, scientists have developed a theory called the standard model to explain all the matter in the universe and how it is held together. The model includes only the fundamental particles in the Table 1.2. No other particles are needed to explain all kinds of matter. According... |
in ordinary matter, virtually all quarks are strange quarks and charm quarks. | (A) true (B) false | B | Remember the quarks from the first page of this chapter? Quarks are even tinier particles of matter that make up protons and neutrons. There are three quarks in each proton and three quarks in each neutron. The charges of quarks are balanced exactly right to give a positive charge to a proton and a neutral charge to a ... |
fundamental forces that affect matter include | (A) gravitational force (B) electromagnetic force (C) weak nuclear force (D) all of the above | D | The interactions of matter particles are subject to four fundamental forces: gravity, electromagnetic force, weak nuclear force, and strong nuclear force. All of these forces are thought to be transmitted by bosons, the force- carrying fundamental particles. The different types of bosons and the forces they carry are s... |
gamma rays | (A) are waves of electric and magnetic energy (B) travel at the speed of light (C) have more energy than any other electromagnetic waves (D) all of the above | D | Gamma rays are the most dangerous type of radiation. They can travel farther and penetrate materials more deeply than can the charged particles emitted during alpha and beta decay. Gamma rays can be stopped only by several centimeters of lead or several meters of concrete. Its no surprise that they can penetrate and da... |
radioactive nuclei undergo decay because they are unstable. | (A) true (B) false | A | Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radioactive decay is a nuclearrather than chemicalreaction bec... |
in gamma decay, both particles of matter and energy are emitted. | (A) true (B) false | B | In alpha and beta decay, both particles and energy are emitted. In gamma decay, only energy is emitted. Gamma decay occurs when an unstable nucleus gives off gamma rays. Gamma rays, like rays of visible light and X-rays, are waves of energy that travel through space at the speed of light. Gamma rays have the greatest a... |
gamma decay results in a nucleus with a different number of protons. | (A) true (B) false | B | Both alpha and beta decay change the number of protons in an atoms nucleus, thereby changing the atom to a different element. In alpha decay, the nucleus loses two protons. In beta decay, the nucleus either loses a proton or gains a proton. In gamma decay, no change in proton number occurs, so the atom does not become ... |
higher-energy electromagnetic waves have lower frequencies. | (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... |
gamma rays have wavelengths shorter than the nucleus 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... |
the frequencies of gamma rays are | (A) higher than 1019 hertz (B) lower than a billion waves per second (C) higher than the frequencies of X rays (D) two of the above | D | 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... |
sources of gamma rays include | (A) the sun (B) collapsing stars (C) radioactive decay (D) all of the above | D | Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect liv... |
gamma rays from space are absorbed by earths atmosphere. | (A) true (B) false | A | Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect liv... |
gamma rays can pass through | (A) bones (B) teeth (C) skin (D) all of the above | D | The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer. Ironically, the deadly effects of gamma rays can be used to treat cancer. In th... |
gravity acts only between objects that are touching. | (A) true (B) false | B | Gravity has traditionally been defined as a force of attraction between things that have mass. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. Gravity can act between objects that are not even touching. In fact, gravity can act over very long distanc... |
the strength of gravity between two objects depends on their | (A) size (B) volume (C) mass (D) all of the above | C | Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly tha... |
which of the following objects has the greatest gravity? | (A) the moon (B) the sun (C) Earth (D) you | B | Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly tha... |
there is gravitational attraction between you and every object around you. | (A) true (B) false | A | You are already very familiar with Earths gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects above the surface, from meteors to skydivers, down to the ground. Gravity betwee... |
weight is measured with a balance. | (A) true (B) false | B | Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measure... |
the groups in question 1 are the only groups in the periodic that contain elements in more than one class. | (A) true (B) false | A | Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also con... |
metalloids include the element | (A) gallium (B) phosphorus (C) selenium (D) germanium | D | Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between ... |
which of the following is a property of metalloids? | (A) malleability (B) brittleness (C) dullness (D) all of the above | B | Most metalloids have some physical properties of metals and some physical properties of nonmetals. For example, metals are good conductors of both heat and electricity, whereas nonmetals generally cannot conduct heat or electricity. And metalloids? They fall between metals and nonmetals in their ability to conduct heat... |
which of the following statements is (are) true of boron? | (A) It has three valence electrons (B) It is fairly reactive (C) It is a solid at room temperature (D) all of the above | D | Group 13 of the periodic table is also called the boron group because boron (B) is the first element at the top of the group (see Figure 1.2). Boron is also the only metalloid in this group. The other four elements in the groupaluminum (Al), gallium (Ga), indium (In), and thallium (Tl)are all metals. Group 13 elements ... |
carbon is a metalloid. | (A) true (B) false | B | Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. |
all group 15 elements are very reactive. | (A) true (B) false | B | The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are eager to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of elec... |
which of the following elements is not a halogen? | (A) bromine (B) chlorine (C) selenium (D) iodine | C | Halogens are highly reactive nonmetallic elements in group 17 of the periodic table. As you can see in the periodic table 1.1, the halogens include the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). All of them are relatively common on Earth except for astatine. Astatine is radioacti... |
the halogen named astatine is radioactive. | (A) true (B) false | A | Halogens are highly reactive nonmetallic elements in group 17 of the periodic table. As you can see in the periodic table 1.1, the halogens include the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). All of them are relatively common on Earth except for astatine. Astatine is radioacti... |
halogens tend to form compounds with elements in group | (A) 1 (B) 2 (C) 16 (D) 18 | A | Elements in group 17 are called halogens (see Figure 6.13). They are highly reactive nonmetals with seven valence electrons. The halogens react violently with alkali metals, which have one valence electron. The two elements combine to form a salt. For example, the halogen chlorine (Cl) and the alkali metal sodium (Na) ... |
all halogens are gases at room temperature. | (A) true (B) false | B | The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine i... |
properties of halogens include | (A) relatively low melting point (B) ability to conduct electricity (C) ability to conduct heat (D) all of the above | A | The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine i... |
functions of the ear include | (A) gathering sound waves (B) amplifying sound waves (C) changing sound waves to electrical signals (D) all of the above | A | The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hea... |
all of the following are parts of the outer ear except the | (A) pinna (B) ear canal (C) oval window (D) eardrum | C | The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel thr... |
the main role of the middle ear is to change sound waves to electrical impulses. | (A) true (B) false | B | The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, ... |
the inner ear includes the | (A) stirrup (B) cochlea (C) anvil (D) all of the above | B | The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel thr... |
you perceive a sound as soon as the sound waves strike your eardrum. | (A) true (B) false | B | Hearing is the ability to sense sound. Sound travels through the air in waves, much like the waves you see in the water pictured below ( Figure 1.1). Sound waves in air cause vibrations inside the ears. The ears sense the vibrations. The human ear is pictured below ( Figure 1.2). As you read about it, trace the path of... |
the most common cause of hearing loss is | (A) loud sounds (B) infections (C) injuries (D) none of the above | A | All these structures of the ear must work well for normal hearing. Damage to any of them, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. To learn more about hearing loss, watch the animation at this URL: (1:39). MEDIA Click image to the left or use the URL below. URL: Most a... |
loud sounds cause loss of hearing by damaging the tiny bones of the middle ear. | (A) true (B) false | B | Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. |
louder sounds damage hearing more quickly than softer sounds. | (A) true (B) false | A | The most common cause of hearing loss is exposure to loud sounds. Loud sounds can damage hair cells inside the ears. Hair cells change sound waves to electrical signals that the brain can interpret as sounds. Louder sounds, which have greater intensity than softer sounds, can damage hair cells more quickly than softer ... |
hearing loss caused by loud sounds is temporary. | (A) true (B) false | B | Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. |
the permissible exposure time to a 97-decibel sound is | (A) 1 minute (B) 4 minutes (C) 30 minutes (D) 4 hours | C | The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper,... |
heat is a form of energy. | (A) true (B) false | B | Heat and light are forms of energy. Other forms are chemical and electrical energy. Energy cant be created or destroyed. It can change form. For example, a piece of wood has chemical energy stored in its molecules. When the wood burns, the chemical energy changes to heat and light energy. |
temperature measures the average kinetic energy of particles. | (A) true (B) false | A | No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. W... |
thermal energy always moves from cooler to warmer substances. | (A) true (B) false | B | Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see ... |
thermal energy is transferred between two substances until | (A) one substance is warmer than the other (B) both substances are warmer than they were (C) both substances are cooler than they were (D) both substances have the same temperature | D | Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see ... |
thermal energy is transferred between substances only when they have different | (A) masses (B) volumes (C) temperatures (D) two of the above | C | Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see ... |
thermal energy can be transferred by | (A) conduction (B) convection (C) radiation (D) all of the above | D | The bonfire from the opening image has a lot of thermal energy. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Thermal energy from the bonfire is transferred to the hands by thermal radiation. Thermal radiation is the transfer of thermal ener... |
thermal energy is always transferred | (A) from a cooler to warmer object (B) from a warmer to cooler object (C) between objects that are the same temperature (D) two of the above | B | The bonfire from the opening image has a lot of thermal energy. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Thermal energy from the bonfire is transferred to the hands by thermal radiation. Thermal radiation is the transfer of thermal ener... |
only the particles of warm matter are in constant random motion. | (A) true (B) false | B | The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. |
all of the following are examples of heat conduction except | (A) pressing a shirt with a hot iron (B) warming your hands by holding a cup of hot chocolate (C) warming your hands over a campfire (D) heating soup in a pan on a stovetop | C | The cookie sheet in the opening image transfers thermal energy to the cookies and helps them bake. There are many other common examples of conduction. The Figure 1.1 shows a few situations in which thermal energy is transferred in this way. Q: How is thermal energy transferred in each of the situations pictured in the ... |
if you hold an ice cube in your hand, your hand feels really cold because | (A) cold is transferred to your hand from the ice cube (B) thermal energy is transferred from your hand to the ice cube (C) thermal energy is transferred to your hand from the ice cube (D) none of the above | B | Think about how you would make ice cubes in a tray. First you would fill the tray with water from a tap. Then you would place the tray in the freezer compartment of a refrigerator. The freezer is very cold. What happens next? |
conduction occurs when particles of matter collide. | (A) true (B) false | A | To understand how conduction works, you need to think about the tiny particles that make up matter. The particles of all matter are in constant random motion, but the particles of warmer matter have more energy and move more quickly than the particles of cooler matter. When particles of warmer matter collide with parti... |
a hot-water heating system includes | (A) ducts (B) pipes (C) registers (D) two of the above | B | A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a... |
in a hot-water heating system, hot water transfers thermal energy to radiators by thermal radiation. | (A) true (B) false | B | A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a... |
in both hot-water and warm-air heating systems, thermal energy is transferred through the air in each room by conduction. | (A) true (B) false | B | A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a... |
a warm-air heating system includes | (A) ducts (B) pipes (C) registers (D) two of the above | D | A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts ... |
hydrocarbons are the simplest type of carbon compounds. | (A) true (B) false | A | Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds. Nonetheless, they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms, but large hydrocarbons may have hundreds. The size of hydrocarbon molecules influences ... |
hydrocarbon molecules | (A) are polar (B) do not dissolve in water (C) are all liquids at room temperature (D) two of the above | B | Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical fo... |
hydrocarbons are used to make | (A) fuels (B) waxes (C) fabrics (D) all of the above | D | It is hard to overstate the importance of hydrocarbons to modern life. Hydrocarbons have even been called the driving force of western civilization. You saw some ways they are used in the opening image. Several other ways are pictured in the Figure 1.1. The most important use of hydrocarbons is for fuel. Gasoline, natu... |
the size of hydrocarbon molecules influences their melting and boiling points. | (A) true (B) false | A | The size of hydrocarbon molecules influences their properties, including their melting and boiling points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar, which means that their molecules do not have oppositely charged sides. Therefo... |
hydrocarbons consist only of carbon and hydrogen atoms. | (A) true (B) false | A | Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical fo... |
saturated hydrocarbons | (A) contain only single bonds between carbon atoms (B) contain as many hydrogen atoms as possible (C) are called alkanes (D) all of the above | D | Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an examp... |
what is the general formula for a saturated hydrocarbon? | (A) CnH2n+2 (B) CnH2n (C) CnH2n-2 (D) none of the above | A | Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an examp... |
elements in group 1 of the periodic table include | (A) sodium (B) hydrogen (C) calcium (D) two of the above | D | Sodium (Na) is an element in group 1 of the periodic table of the elements. This group (column) of the table is shown in Figure below. It includes the nonmetal hydrogen (H) and six metals that are called alkali metals. Elements in the same group of the periodic table have the same number of valence electrons. These are... |
how many valence electrons do alkali metals have? | (A) 1 (B) 2 (C) 3 (D) 4 | A | 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... |
hydrogen and alkali metals are very reactive. | (A) true (B) false | A | Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least react... |
the most reactive alkali metal is lithium. | (A) true (B) false | B | Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least react... |
characteristics of alkali metals include | (A) softness (B) high density (C) liquid state at room temperature (D) two of the above | A | Besides being very reactive, alkali metals share a number of other properties. Alkali metals are all solids at room temperature. Alkali metals are low in density, and some of them float on water. Alkali metals are relatively soft. Some are even soft enough to cut with a knife, like the sodium pictured in the Figure 1.1... |
the alkali metal named francium is radioactive. | (A) true (B) false | A | Although all group 1 elements share certain properties, such as being very reactive, they are not alike in every way. Three different group 1 elements are described in more detail below. Notice the ways in which they differ from one another. Q: Why do you think hydrogen gas usually exists as diatomic molecules? A: Each... |
water is a polar compound. | (A) true (B) false | A | Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. O... |
hydrogen bonds are very strong bonds. | (A) true (B) false | B | Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur n... |
in water, hydrogen bonds hold together | (A) hydrogen and oxygen atoms in the same molecule (B) hydrogen and oxygen atoms in different molecules (C) hydrogen atoms in different molecules (D) hydrogen atoms in the same molecule | B | Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur n... |
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