Teacher Guide & Answers

ReinforcementSection 1 (page 1)1. State the problem.2. Gather information.3. Form a hypothesis.4. Test the hypothesis with an experiment.5. Analyze data.6. Reach a conclusion.7. Report results.8. International System of Units9. a10. c11. b12. The drug is the variable, and the three peoplewho are injected with the harmless solutionmake up the control.13. Being aware of possible hazards and takingprecautions can prevent accidents in the sciencelaboratory.14. A theory is an explanation based on manyobservations. Theories can be changed as newinformation is gathered. A law is a rule ofnature.

Section 2 (page 2)1. Living things grow.2. Living things reproduce.3. Living things are made of one or more cells;living things are organized.4. Living things grow and develop.5. Living things use energy.6. Living things respond and adjust to changes intheir environment.7. Living things have a life span.8. Living things take in and use energy.9. a stimulus10. a response11. homeostasis12. cells

Section 3 (page 3)

1. He showed that maggots come from the eggslaid by flies on meat, not from the meat itself.2. He showed that a sealed flask of boiled brothdeveloped no tiny organisms.3. He showed that broth became contaminatedonly when it was exposed to the air.4. Living things come spontaneously from nonliving matter.5. Living things come only from living things.6. lightning, energy from the Sun, and Earth’s heat7. They became part of what is often called the“primordial soup” and could have combined toform the more complex compounds found inliving things.

Section 4 (page 4)1. Different organisms may go by the same common name in different places. Scientists would have difficulty sharing information.2. a. to avoid errors in communicationb. to classify organisms with similar evolutionary history togetherc. to give descriptive information about thespeciesd. to organize and easily find information aboutorganisms3. smooth4. 8–125. It peels.

Directed Reading for Content MasteryOverview (page5)Step 1: state the problemStep 2: gather informationStep 3: form a hypothesisStep 5: analyze dataStep 6: draw conclusionsStep 7: report results1. organism2. biogenesis3. nomenclature4. cell

5. genus

Section 1 and 2 (page 6)1. variable2. hypothesis3. Homeostasis4. cells5. organized6. respond7. energy8. grow and develop9. reproduce

Sections 3 and 4 (page 7)1. spontaneous generation2. Louis Pasteur3. species4. Scientific5. Common name: mountain lionScientific name: Felis concolorGenus: Felis

Key Terms (page 8)1. kingdom2. homeostasis3. cell4. law5. control6. phylogeny7. organism8. theory9. biogenesis10. genus11. variable

Chapter ReviewPart A. Vocabulary Review (page 9)1. organisms (3/2)2. cells (3/2)3. binomial nomenclature (9/4)4. kingdom (9/4)5. law (1/1)6. homeostasis (3/2)7. phylogeny (9/4)8. genus (9/4)

9. spontaneous generation (5/3)10. biogenesis (6/3)11. scientific methods (1/1)12. hypothesis (1/1)13. variable (1/1)14. control (1/1)15. theory (1/1)16. Critical thinking (1/1)17. law (1/1)18. measurement (2/1)19. volume (2/1)20. experiment (1/1)

Part B. Concept Review (page 10)1. spontaneous generation (5/3)2. maggots (5/3)3. nonliving (6/3)4. biogenesis (6/3)5. oxygen (7/3)6. living (7/3)7. a. meter (2/1) b. kilometer (2/1) c. kilogram (2/1) d. gram (2/1) e. degree (2/1) f. liter (2/1)8. Living things are made up of one or more cells, use energy, move, respond to their environment, reproduce, grow, develop, adapt, and have a life span. (3/2)9. Nonliving things such as water, oxygen, andcarbon dioxide are needed by living things to survive. These materials are returned to the environment and are used again. (4/3)10. Answers will vary but should demonstrate an understanding of the need to experiment and examine data and conditions carefully. (10/4)11. Errors might have been made during the experiment, such as an error in measuring or recording data. There might have been an unknown influence affecting the dependent variable. (6/2)

ReinforcementSection 1 (page 11)1–3. Accept any three of the following, or otherreasonable answers: wings that enable the bat to

fly; ability to give off high-frequency sounds;large ears that allow it to hear sounds bouncedoff insects; jointed feet to grasp prey.4–5. Accept any two of the following or otherreasonable answers: dark upper surface makes itinconspicuous to flying predators; light bellymakes it less conspicuous to predators lookingup from below; fins enable fish to swim away;mouth has teeth for defense.

Section 2 (page 12)1. estimate2. evolution3. DNA4. homologous structures5. vestigial structures6. sedimentary rock7. relative dating and radiometric dating8. The fossil record is incomplete because notevery living thing does or can become fossilized.9. embryology, vestigial structures, homologousstructures, similarities in DNA10. No, radiometric dating does not produce exact results because the original amount of radioactive element in a rock layer is never completely certain.

Directed Reading for Content MasteryOverview (page 13)1. gradualism2. punctuated equilibrium3. slowly

Sections 1 (page 14)1. Lamarck2. Darwin3. mutations4. punctuated equilibrium5. does6. are not7. differences8. can

9. were10. Populations11. are

Section 2 (page 15)1. radioactive2. embryology3. sedimentary4. fossils5. vestigial6. homologous7. traits

Key Terms (page 16)

1. species2. evolution3. selection4. gradualism5. punctuated equilibrium6. sedimentary7. element8. embryology9. vestigial10. variation

Chapter ReviewPart A. Vocabulary Review (page 17)1. evolution (1/1)2. species (1/1)3. variation (2/1)4. natural selection (1/1)5. gradualism (3/1)6. fossils (4/2)7. sedimentary (4/2)8. relative dating (5/2)9. embryology (6/2)10. vestigial structure (6/2)11. homologous (6/2)12. punctuated equilibrium (3/1)13. radioactive element (5/2)

Part B. Concept Review (page 18)1. Characteristics that parents developed during

their lives were passed to their offspring. (1/1)2. Individuals with traits most favorable for aspecific environment survive and pass on thesetraits to offspring. (1/1)3. Gradualism says that evolution is a slow, steady change. Punctuated equilibrium states thatrapid evolution of a species comes about by themutation of a few genes. (3/1)4. Fossils give proof of preexisting, simpler lifeforms and their environment. (4/2)5. a fossil (4/2)6. embryology (6/2)7. vestigial structure (6/2)8. homologous structures (6/2)9. DNA studies (6/2)

ReinforcementSection 1 (page 19)1. d2. a3. b4. e5. c6. f7. false; extinct8. false; threatened9. false; endangered10. false; difficult11. true12. false; often

Section 2 (page 20)1. conservation2. harm3. habitat4. laws5. preserve6. restoration7. reintroduction8. captive9. plant10. extinct11. Conservation biology is the study of methodsfor protecting biodiversity.12. Answers will vary. Students might say thatconservation biologists try to discover why a

species has become endangered and developstrategies to safeguard the species.

Directed Reading for Content MasteryOverview (page 21)1. reduced2. habitats3. divided habitats4. restoration5. habitat preservation6. increase7. allows for stability in8. species9. many

Sections 1 (page 22)1. biodiversity2. prevent3. endangered4. species5. stability6. loss7. extinct8. increases9. threatened10. native11. highest12. improve13. Extinction14. human15. ecosystem

Section 2 (page 23)1. g2. e3. d4. f5. a6. c7. b8. h9. a. to protect a species from harm b. to protect habitat of a species

Key Terms (page 24)1. extinct2. endangered3. threatened4. introduced5. native6. acid rain7. ozone8. conservation

9. restoration10. biodiversity11. captive

Chapter ReviewPart A. Vocabulary Review (page 25)1. threatened (3/1)2. biodiversity (2/1)3. captive population (2/2)4. extinct (3/1)5. conservation biology (4/2)6. acid rain (3/1)7. endangered (3/1)8. reintroduction (6/2)9. ozone depletion (3/1)10. introduced (5/2)11. native (2/1)12. restoration (5/2)13. extinct (3/2)14. endangered (3/2)15. threatened (3/2)

Part B. Concept Review (page 26)1. The most common measure of biodiversity is the number of species that live in an area. (1/1)2. Biodiversity increases because temperatures tend to be higher. (1/1)3. It made it illegal to harm, collect, harass, or disturb the habitat of any species on the endangered or threatened species list. (4/2)4. They allow animals to move from one preserve to another without having to cross roads, farms, or other areas inhabited by humans. (3/1)5. DDT ended up in the food the pelicans ate. Itmade their eggshells so thin that they would break before the chicks inside were ready to hatch. (3/1)6. Answers may vary, but should include that an

introduced species may use up all of the resources needed by native species. (3/1)7. Answers may vary. Habitat loss, pollution, overhunting, and introduced species can threaten or endanger species. (3/1)8. Answers may vary. Humans need and like a variety of foods; biodiversity can help improve food crops and provide useful materials and important medicines. (2/1)9. Answers may vary. Humans affect habitats byreplacing a forest or meadow with pavement,lawns, buildings, and other development; bydividing a habitat; by introducing species; and bypollution. (3/1)

ReinforcementSection 1 (page 27)1. Sample questions:a. How high can it jump?b. How long is its tail?c. How much does it weigh?d. How much does it eat?2. Sample questions:a. How tall is it?b. What is the inside temperature?c. How fast is lava flowing out?d. How often does it erupt?3. about 3 cm4. about 1/2 meter5. about 1 mm6. Answers will vary.7. Student B’s is more accurate because it is closer to the true value.8. It is precise to the nearest hundredth of acentimeter.9. 10 cm10. 9.8 cm

Section 2 (page 28)1. gram or kilogram, pan balance2. degrees Celsius or Kelvins, thermometer3. cubic centimeter or cubic meter, ruler ormeterstick4. meter, meterstick5. milliliter, graduated cylinder

6. second, stopwatch7. 64,000 m8. 0.373 kg9. 89.7 cm10. 250 mL11. (120 km/h) (1,000 m/1 km) (1 h/60 min)(1 min/60 s) = 33.3 m/s12. (33.3 m/s) (60 s/1 min) = 1,998 m/min =2,000 m/min

Section 3 (page 33)1. f2. a3. e4. g or b5. b or g6. d7. c8. g9. c10.

Directed Reading for Content MasteryOverview (page 31)1. temperature 7. tenth2. length 8. liter3. volume 9. hundred4. weight 10. million5. mass 11. giga6. kilo

Section 1 and 2 (page 32)1. 4 cm2. 10 cm is too long.3. Measure the line with a ruler marked inmillimeters.4. 1,0005. 2,0006. one thousandth7. one8. international system9. kilogram10. Kelvin

Sections 2 and 3 (page 33)1. g 8. circle graph2. e 9. bar graph3. b 10. line graph4. a 11. line5. d 12. circle6. c 13. bar7. f

Key Terms ( page 34)1. mass2. table3. circle graph4. SI5. celsius6. bar graph7. Kelvin8. kilogram9. meter10. line graph11. estimation; vertical word: measurement

Chapter ReviewPart A. Vocabulary Review (page 35)Across Down3. 7/3 1. 5/25. 4/2 2. 5/26. 1/1 4. 5/28. 5/2 7. 1/1

9. 6/3 10. 8/311. 6/3 12. 5/213. 8/3

Part B. Concept Review (page 36)1. deci- (5/2)2. 14 cm (1/1)3. line (8/3)4. Accuracy (3/1)5. 1,000 (5/2)6. Weight (5/2)7. equal to (5/2)8. 50% (7/3)9. a. gram (5/2) b. cubic meter (5/2) c. kilometer (5/2) d. Kelvin (5/2) e. micrometer (5/2) f. milliliters/second (5/2)10. a. drawing (6/3) b. photograph (6/3) c. movie (6/3)11. 10% (6/3)12. line graph—only one variable is a number (8/3)13. 72° (7/3)

ReinforcementSection 1 (page 37)1. d2. b3. f4. c5. e6. h

7. a8. g9. j10. i11. k12. l13. c14. b15. d

Section 2 (page 38)1. appearance2. state3–4. liquid, solid5. freezes6. ice7. shape8. different9. color changes10. gain11. energy12. gas13. Answers will vary.14. Answers will vary.

Directed Reading for Content MasteryOverview (page 39)1–3. solid, liquid, gas4. composition5–6. color, odor(For grouped answers, order of answers will vary.)7. T8. T9. T10. F11. F

Sections 1 (page 40)1. d2. c3. a4. e5. b6. Possible answers include: red, hard, roughgravelly surface, rectangular solid7. Possible answers include: yellow, solid, approx 3/4 kg, soft at room temperature8. Possible answers include: yellow paint, woodinterior, solid, graphite core, 2–3 g

9. Possible answers include: shaped like a horseshoe, often with the handle portion painted red, attracts steel, solid10. Possible answers include: white with blue lines, flat, thin, 1–2 g, flammable, solid11. Possible answers include: red/green/red & blue, cylindrical solid filled with liquid which has a high concentration of gas, 355 mL, pressure increases if shaken12. Possible answers include: color, rectangularsolid, made of paper and cardboard, include size,specific mass, and volume.13. Possible answers include: cylinder filled withclear liquid, 360 mL, density = 1 g/cm3,mp = 0°C, bp = 100°C14. Possible answers include: flesh color (studentspecific), solid filled with liquids, 7 cm, movesthrough muscle and ligament connections15. Possible answers include: steel, easily magnetized, 3 1/4 cm × 3/4 cm, silver, solid

Section 2 (page 41)1. physical2. chemical3. chemical4. physical5. chemical6. chemical7. chemical8. physical9. chemical10. physical11. physical12. Physical changes change the way somethinglooks, but the substance stays the same. Chemical changes result in a new substance.13. law of conservation of mass

Key Terms (page 48)

Chapter ReviewPart A. Vocabulary Review (page 43)1. chemical property (1/1)2. chemical change (4/2)3. conservation of mass (3/2)4. physical change (4/2)5. density (1/1)6. physical property (1/1)7. boiling point (1/1)8. behavior (1/1)9. volume (1/1)10. melting point (1/1)11. state (2/1)12. appearance (1/1)

Part B. Concept Review (page 43)1. physical properties (1/1)2. chemical change (4/2)3. chemical (4/2)4. state (3/2)5. liquid state (2/1)6. amount (1/1)7. Density (1/1)8. melting or boiling (2/1)9. behavior (1/1)10. chemical property (1/1)11. Deposition (3/2)12. Color (3/2)13. gained or released (4/2)14. gas or solid (3/2)15. mass, law of conservation of mass (4/2)16. physical (4/2)17. physical (4/2)18. chemical (4/2)19. physical (4/2)20. chemical (4/2)21. physical (4/2)22. chemical (4/2)23. chemical (4/2)24. Answers may include: mass, weight, volume (1/1)25. Answers may include: density, melting point,

boiling point, solubility, ability to attract amagnet, state of matter, color (1/1)

ReinforcementSection 1 (page 45)1. h2. d3. a4. g5. b6. i7. f8. c9. e10. j11. Gravity holds the water molecules at the bottom of the glass, and attractive forces hold the water molecules together as a liquid.12. The attractive (cohesive) forces between water molecules pull them together to form the beads.13. Cohesive forces between water molecules cause surface tension. Within a volume of water,molecules are pulled in all directions, but themolecules are only pulled inward at the surface.14. The force of gravity on a bug can be less thanthe water’s surface tension. The surface tensionwill support the bug and it won’t sink.15. Water begins entering the gaseous state whenmolecules gain enough energy to overcomeattractive forces. At 100°C boiling begins andmolecules below the surface enter the gas phase.

Section 2 (page 46)1. freezing2. boiling3. melting4. evaporating5. Graph B; as heat is added, the temperature first rises, then remains constant as the solid melts, then rises again. This indicates that some of the energy is being used to break the attractive forces between the particles

in the solid. So the solid must be crystalline.6. Graph A represents the melting of an amorphous solid. It shows a continuous increase in temperature which would occur as an amorphous solid got softer. Since there are no crystalline structures to break in an amorphous solid, the heating process is continuous.

Section 3 (page 47)

Directed Reading for Content MasteryOverview (page 49)1. solid2. increases3. liquid4. boiling point5. decreases6. condensation7. pressure8. density

Sections 1 (page 50)1. solid—ice; liquid—water; gas—water vapor2. Water changes state as its molecules move faster or slower or as temperature increases or decreases.3. Accept all reasonable answers. Possible answers include: ice—drinks, skating, preserving food; water—drinking, bathing, swimming; gas— cooking foods, ironing, generating electricity4. The process is the same.

Section 2 and 3 (page 51)

1. This is an example of vaporization. As the liquid boils, it changes into a gas.2. This illustrates Pascal’s principle. Pressure applied at any point to a confined liquid is transmitted unchanged throughout the liquid. So applying pressure anywhere on the bottle makes liquid squirt out of any hole in the bottle.3. This is an example of buoyancy. The liquid water exerts a buoyant force that holds up the floating ice cubes.

Key Terms (page 52)1. d 9. c2. b 10. i3. a 11. f4. n 12. h5. l 13. j6. m 14. o7. e 15. k8. g

Chapter ReviewPart A. Vocabulary Review (page 53)1. e (2/1) 9. g (4/2)2. j (1/1) 10. f (4/2)3. m (3/2) 11. c (6/3)4. h (4/2) 12. l (3/2)5. o (3/2) 13. k (7/3)6. a (4/2) 14. i (6/3)7. p (4/2) 15. n (6/3)8. b (4/2) 16. d (6/3)

Part B. Concept Review (54)1. specific heat (2/1)2. crystalline solids (2/2)3. solid; liquid (2/1)4. liquid (2/1)5. vaporization (4/2)6. evaporation (4/2)7. condensation (4/2)8. releases (4/2)9. sinks (6/3)10. The line on the graph would rise smoothly until it approached 100°C. The temperature levels off at the boiling point as the water changes into water vapor. (5/2)11. Molecules in a gas have escaped completelyfrom the attractions of neighboring molecules.

They are very far apart and are free to moveuntil they collide with a barrier, such as thewalls of the container. (2/1)12. Water molecules are excreted by our skin. The thermal energy from our body is transmitted as heat. The thermal energy heats the water molecules and causes them to evaporate. (4/2)13. Molecules throughout the water press againsteach other, transmitting the pressure unchangedthroughout the fluid. (7/3)

ReinforcementSection 1 (page 55)1. Dalton2. Thomson3. Rutherford4. electron cloud5. proposed that matter is composed of tinyparticles called atoms6. proposed that atoms could not be divided intosmaller pieces; that atoms of the same elementare exactly alike; and different elements aremade of different kinds of atoms7. discovered cathode rays, which he said werestreams of negatively charged particles8. Proved that atoms were made up of smaller,negatively charged particles—electrons.Postulated that atoms must also containpositively charged particles that neutralize thecharge of the electrons.9. Hypothesized that most of an atom’s mass and all its positive charge were contained in a smallnucleus, with the rest being empty space occupied by almost massless electrons. Also hypothesized the existence of neutrally charged particles in the nucleus.

10. No. Electrons are in unpredictable motion. They are probably close to the nucleus, but may be anywhere.11. Since electrons came from every kind of cathode material, Thomson inferred that they arepart of all atoms. This means they are smaller.

Section 2 (page 56)1. The atomic number is the number of protons in the nucleus of the atom.2. Isotopes are atoms of the same element thathave different numbers of neutrons.3. The strong nuclear force is the force that holdsthe protons and the neutrons together in thenucleus of the atom.4. alpha particle ejection, and beta particle emission5. During transmutation one element changes into another through radioactive decay.6. Radioactive decay is the release of nuclearparticles and energy.7. An alpha particle consists of two protons andtwo neutrons.8. A beta particle is a high-energy electron thatcomes from the nucleus rather than the electroncloud.9. A half-life is the amount of time required forhalf of a sample of a radioactive isotope to decay.10. Nuclear waste products are a problem because they continue to produce harmful radiation for long periods of time. Special disposal sites that separate the nuclear waste products from humans are necessary.11. Tracer elements are radioactive isotopes used in hospitals and clinics to diagnose diseases. Tracer elements are also used by scientific laboratories to study environmental conditions.12. False. These isotopes should have short half-lives to avoid damage from radiation.13. True

14. False. Archaeologists use carbon dating to determine the age of dead animals, plants, and humans.15. False. The half-life of an isotope stays the same.

Directed Reading for Content MasteryOverview (page 57)1. nucleus2. electron cloud3. protons4. neutrons5. electrons6. positive7. negative8. electrons9. mass number10. alpha11. Transmutation

Sections 1 (page 58)1. proton2. electron3. nucleus4. neutron5. The atom shown is more like Rutherford’s than like Thomson’s. It shows a small, dense nucleus with electrons in the space around the nucleus. Rutherford’s model had a nucleus; Thomson’s had the electrons imbedded in the positively charged material.6. Thomson used magnets to bend the rays. Magnets do not affect light, so Thomson concluded that the rays were not light.7. In a cathode-ray tube, the particles originate atthe cathode and move toward the anode.

Section 2 (page 59)1. isotope2. atomic number3. mass number4. average atomic mass5. nucleus6. archaeologist7. transmutation8. americium9. alpha particle10. half-life11. beta particle

12. radioactive decay13. thyroid14. strong nuclear

Key Terms (page 60)

Chapter ReviewPart A. Vocabulary Review (page 61)1. d (4/1) 12. k (5/2)2. g (1/1) 13. e (5/2)3. l (3/1) 14. h (6/2)4. a (3/1) 15. chemistry (4/1)5. f (3/1) 16. atoms (4/1)6. c (3/1) 17. anode (1/1)7. i (5/2) 18. cathode (1/1)8. b (5/2) 19. sphere (3/1)9. n (5/2) 20. random (5/2)10. m (5/2) 21. tracer elements (7/2)11. j (5/2)

Part B. Concept Review (page 62)1. nucleus (3/1)2. neutron (3/1)3. proton (3/1)4. electron (3/1)5. electron cloud (3/1)6. atom (1/1)7. atom (4/1)8. cathode rays (1/1)9. neutron (3/1)10. equal to (5/2)11. protons (3/1)12. subtract the atomic number (6/2)13. 1 (6/2)

ReinforcementSection 1 (page 63)1. Atomic number2. Element symbol3. Element name4. Average atomic mass

5. e6. c7. b8. a9. h10. f11. g12. d

Section 2 (page 64)1. Group 1 elements are called the alkali metals.2. Group 2 elements are called the alkaline earthmetals.3. Except for hydrogen, Groups 1 and 2 are solidmetals.4. The other groups may contain metals, nonmetals, and metalloids.5. carbon6. Ammonia is made of nitrogen and hydrogen.Possible uses: cleaner, disinfectant, fertilizer,refrigerant, to freeze-dry foods7. Ozone shields living things from some harmful radiation from the Sun.8. They all form salts with sodium and other alkali metals.9. They all rarely combine with other elements.

Section 3 (page 65)1. metals2. magnetic3. poisonous4. Tungsten5. Mercury6. platinum7. lanthanides8. lanthanides9. radioactive10. synthetic11. f12. i13. g14. h15. j16. a17. b18. e19. c20. d

Directed Reading for Content MasteryOverview (page 67)1. Students should circle all of the elements inGroup 18.2. Students should draw an “X” through hydrogen. Its atomic number is 1.3. Students should draw a box around the Actinides.4. Students should underline oxygen, sulfur, selenium, tellurium, polonium, and ununhexium.5. Students should draw a line through and listsodium, magnesium, aluminum, silicon,phosphorus, sulfur, chlorine, and argon.

Sections 1 (page 68)1. atomic number2. element symbol3. element name4. atomic mass5.

6.

7. transition8. Metals9. True10. periods

Section 2 and 3 (page 69)1. cerium2. iodine3. potassium4. lead5. boron6. calcium7. krypton8. einsteinium

9. radioactive10. nonmetal11. hydrogen12. liquid13. rarely14. inner transition

Key Terms (page 70)1. period2. representative3. group4. metal5. nonmetal6. metalloid7. semiconductor8. transition9. catalyst10. synthetic

Chapter ReviewPart A. Vocabulary Review (page 71)1. nonmetal (3/1)2. representative elements (3/1)3. group (3/1)4. metal (3/1)5. metalloid (3/1)6. period (3/1)7. semiconductor (6/2)8. catalyst (7/3)9. Transition elements (7/3)10. Synthetic elements (8/3)

Part B. Concept Review (page 71)1. mercury (2/1)2. helium (2/1)3. nobelium (2/1)4. carbon (2/1)5. sodium (2/1)6. mass number (1/1)7. Hg (3/1)8. neon (4/2)9. actinides (8/3)10. Copper (4/2)11. representative elements (3/1)12. Iron (7/3)13. semiconductor (5/2)14. noble gases (4/2)15. metals (3/1)16. brittle (3/1)17. malleable (3/1)18. hydrogen (3/1)19. fluorine (4/2)20. lead (4/2)21. nickel (7/3)

22. higher (7/3)23. Lanthanides (8/3)24. actinides (8/3)25. mercury (7/3)

ReinforcementSection 1 (page 73)1. outer energy level2. electron3. nucleus4. electron cloud5. electron dot diagram6. element families7. period8. atomic structure9. The elements in the same column of the periodic table (same group, or family) all have the same number of electrons in their outer energy levels.

Section 2 (page 74)1. losing2. positive3. protons4. electrons5. gains6. negative7. ionic8. regular9. electrons10. molecules11. ions12. nonpolar13. covalent14. polar15. covalent16. 1 atom potassium; 1 atom iodine17. 2 atoms sodium; 1 atom sulfur18. 1 atom silicon, 2 atoms oxygen19. 2 atoms hydrogen, 1 atom carbon, 3 atomsoxygen20. H2S ions

Directed Reading for Content MasteryOverview (page 75)1. electron cloud2. nucleus3. covalent4. gain or loss of electrons5. molecule

Section 1 (page 76)

5. No, because its outer energy level is completely filled with eight electrons.6. phosphorus or P7. halogen family8. beryllium, magnesium, strontium, barium, radon

Section 2 (page 77)

Key Terms (page 78)1. ionic bond2. ion3. chemical bond4. compound5. covalent bond6. molecule7. formula8. electron dot diagram9. polar bond10. polar molecule11. electron cloud12. metallic bond

Chapter ReviewPart A. Vocabulary Review (page 79)

Across4. (1/2)5. (3/1)7. (1/2)8. (2/2)10. (2/2)11. (1/1)Down1. (4/2)2. (1/2)3. (4/2)6. (3/2)9. (3/2)

Part B. Concept Review (page 79)1. compound (2/2)2. positive, negative (2/2)3. nucleus, protons, neutrons (1/1)4. lowest (2/1)5. polar bond (3/2)6. nonpolar bond (3/2)7. carbon, two (4/2)8. Electron dot diagrams are very useful becausethey show us the number of electrons in theouter energy levels of an element. Chemicalproperties, such as behavior around otherelements, and physical properties, such as hardness, depend on this atomic structure. (1/1)9. Elements can gain the stable atomic structure of a noble gas by either gaining or losing electrons. Two examples are sodium, which, when it loses an electron, has the same atomic structure as neon, a noble gas; and chlorine, which when it gains an electron, has the same atomic structure as argon, another noble gas. (1/2)10. The two atoms would form an ionic bond,creating the compound sodium chloride—ordinary table salt. (2/2)11. A stairway is a good model because each energy level can be represented as a step. The lowest step is the lowest energy level, containing electrons that are closest to the nucleus. The upper steps are higher energy levels, containing electrons that have more energy and are farther from the nucleus. (2/1)12. In a nonpolar bond, electrons are shared equally by atoms. In a polar bond, electrons are shared unequally. (3/2)

ReinforcementSection 1 (page 81)1. the formation of new substances that haveproperties different from those of the originalsubstance

2. changes in its physical properties, such as its size and shape or its state (solid, liquid, or gas)3. reactants; products4. reactants; products; produces5. a. A word equation can be very long. b. A chemical equation indicates the number of atoms contained in each molecule.6. They indicate the number of atoms of a particular element that are in a particular molecule.7. The law of conservation of mass explains thatthe mass of the products of a chemical reactionis always the same as the mass of the reactantsin that reaction. The atoms have just changedpartners to form new chemical bonds.8. It is a reaction that releases energy.9. It is a reaction that absorbs energy.10. a. Yes b. No c. Yes d. No

Section 2 (page 82)

Directed Reading for Content MasteryOverview (page 83)1. reactant2. endothermic3. heat energy4. heat energy5. rate of reaction6–8. temperature, concentration, catalysts

For grouped answers, order of answers will vary

Sections 1 (page 84)

Section 2 (page 85)1. true2. true3. false; Heat, light, or odor indicate a chemicalchange.4. true5. false; Cold slows down reaction rates.6. true7. false; Chemical reactions occur faster if thereactant is smaller.

Key Terms (page 86)1. i2. f3. b4. g5. h6. c7. d8. a9. e

Chapter Review

Part A. Vocabulary Review (page 87)1. c (1/1)2. f (6/2)3. d (3/1)4. i (1/1)5. a (3/1)6. g (1/1)7. b (6/2)8. e (3/1)9. h (5/2)

Part B. Concept Review (page 87)1. B (2/1)2. U (2/1)3. U (2/1)4. B (2/1)5. d (1/1)6. c (6/2)7. d (6/2)8. a (3/1)9. c (3/1)10. a (1/1)11. d (6/2)12. d (6/2)13. c (2/1)14. c (3/1)15. b (2/1)

ReinforcementSection 1 (page 101)1. precipitate2. physical3. homogeneous4. mixtures5. solutions6. solvent7. solute8. fractionation9. alloy10. chemistry

Section 2 (page 90)1. unequally2. true3. unequally4. true5. ionic6. true7. true8. solvent9. true10. much of11. how much solute dissolves in 100 g of solvent at a given temperature

12. a solution that can dissolve more solute13. Excess solute is dissolved in a hot solution. The solution is cooled slowly, leaving the excesssolute still in the solution.14. It will not dissolve.15. Yes, it increases the amount of gas that can be dissolved in a liquid.16. The amount of most nongaseous solutes that can dissolve in liquid solvents rises with temperature.

Section 3 (page 91)1. water2. It has lost a positive ion.3. The four-atom ion would be a hydronium ion.4. acidic5. Yes, the ions can carry electric charges in acurrent.6. sour taste, electrical conductivity, corrosive,reaction with certain metals forming hydrogengas7. slippery feel, bitter taste, corrosive, electricalconductivity8. hydronium ion9. hydroxide ion10. The pH scale is used to compare the relativestrength of acids and bases.11. neutralizationDirected Reading for Content MasteryOverview (page 93)1. heterogeneous2. homogeneous3. molecular level4. solute5. solvent6. substance that dissolves7. solution8. solute9. solvent

Section 1 and 2 (page 94)1. This will not form a solution. The pebbles are not soluble in water.2. This will form a solution. The sugar is soluble in water.

3. This will not form a solution. Baby oil will float on water.4. aqueous5. composition6. compound7. solid-solid

Sections 3 (page 95)1. 72. 73. 7.54. 15. base6. 77. base8. hydrogen ions9. sour10. tissues11. electricity12. substances13. hydroxide ions14. slippery15. bitter16. corrosive17. electricity

Key Terms (page 96)1. b 6. b2. a 7. b3. b 8. a4. a 9. b5. b 10. a

Chapter ReviewPart A. Vocabulary Review (page 97)1. l (3/1)2. d (7/2)3. o (3/1)4. i (12/3)5. c (9/3)6. b (5/2)7. j (11/3)8. n (3/1)9. e (7/2)10. g (9/3)11. k (7/2)12. m (3/1)13. h (1/1)14. f (7/2)15. a (9/3)

Part B. Concept Review (page 98)1. alloy (4/1)2. true (3/1)3. true (7/2)

4. solubility (8/2)5. true (4/1)6. high (7/2)7. true (3/1, 5/2)8. increases (4/1)9. volume (7/2)10. true (9/3)11. does not (9/3)12. cannot (6/2)13. red (11/3)14. acid-base (12/3)15. true (11/3)

ReinforcementSection 1 (page 99)1. false; The world around you contains manytypes of matter.2. true3. true4. false; Metals have the properties of conductivity, magnetism, and malleability.5. false; Alloys have the properties of metals.6. false; Early ceramics were made from clay that was heated and fired to make it strong.7. true

Section 2 (page 100)1. A scientist works to learn more scientific information and an engineer tries to apply scientific information to solve a problem or human need.2. artifact or hardware; methodology or technique; system of production; social-technical system3. He used standardized parts and a productionline to manufacture a product.4. to create crops that are resistant to herbicidesand insects5. Biomechanical engineers use their knowledge of mechanical devices and machines to repair orreplace defective body parts. Bioelectrical engineers use their knowledge of electricity andelectrical devices to repair defective body parts.Biochemical engineers use their knowledge of

chemistry to artificially duplicate normal bodyfunctions.6. heart pacemaker and defibrillator

Section 3 (page 101)1. defining the problem2. to find other ideas that have been tried and succeeded or failed3. Marketing professionals ensure that the finalproduct can be sold. Environmental professionalsensure that the environment is not harmed in the manufacturing process.4. Quality control ensures that high quality products without defects are made.5. Patent laws protect technological inventions.Copyright laws protect literary and artisticworks. Trademarks protect words or symbolsthat identify brands, goods, or services in themarketplace.

Directed Reading for Content MasteryOverview (page 103)1. Engineers2. chemical properties3. physical properties4. technology

Section 1 (page 104)1. f2. h3. b4. g5. d6. c7. e8. a9. The chemical composition and structure of amaterial.10. All branches of science are concerned withmaterials selection.11. Because they vary widely in their chemical composition and structure.

Sections 2 and 3 (page 105)

1. a2. b3. a4. b5. a6. a7. a8. b

Key Terms (page 106)1. computer simulation2. material3. brainstorming4. technology5. constraints6. materials science7. scientist8. engineer9. malleability10. quality control11. conductivity12. magnetism

Chapter ReviewPart A. Vocabulary Review (page 107)1. k (1/1)2. g (2/1)3. n (1/1)4. h (2/1)5. d (3/1)6. m (2/1)7. e (2/1)8. l (4/2)9. b (6/2)10. a (7/3)11. i (7/3)12. o (5/2)

Part B. Concept Review (page 108)13. Scientists and engineers review the physical and chemical properties of materials to determine their usefulness. (1/1)14. Ceramics and polymers vary widely in theirchemical composition. The chemical composition determines their physical and chemical properties. (3/1)15. A scientist works to learn more scientificinformation and an engineer applies scientificinformation to solve a problem or human need.

(4, 5/2)16. Check students’ answers. (5/2)17. Companies apply for a patent for a new product or invention. (8/3)

ReinforcementSection 1 (page 109)1. T2. F3. F4. T5. T6. T7. T8. F9. F10. T11. F12. F13. T14. T15. T16. motion

Section 2 (page 110)1. g2. d3. j4. h5. f6. k7. i8. downward at a right angle9. true10. slow11. gravity

Section 3 (page 111)1. The wings push air down and back; air pushesup and forward.2. The first car pushes against the second; thesecond car pushes back, causing it to slow.3. Your hand pushes forward; the air pushes yourhand backward.4. Your foot pushes the ground backward; theground pushes your foot forward.5.Your nose feels your finger; your finger feels your nose.6. opposite reaction7. delay

8. inertia9. size; directions10. backward; forward; forward11. The size of the paddle could be larger, or more paddles could be used.

Directed Reading for Content MasteryOverview (page 113)1. a net force2. the direction of the force3. an equal but opposite reaction4. 15. 26. 3

Section 1 and 3 (page 114)1. Second Law of Motion. The force necessary to move the space shuttle is equal to its mass times its acceleration.2. First Law of Motion. The rock stays at rest at the top of the hill until the boy applies force that sends it rolling downhill.

Sections 2 (page 115)1. gravity 6. attraction2. acceleration 7. mass3. force 8. velocity4. normal force 9. accelerate5. Newtons

Key Terms (page 116)1. net force2. force3. friction4. acceleration5. normal force6. third law7. second law8. inertia

Chapter ReviewPart A. Vocabulary Review (page 117)1. a (2/1)2. i (4/2)3. f (4/2)4. h (1/1)5. b (1/1)6. e (1/1)7. g (6/3)8. c (1/1)

9. d (3/1)10. accelerate (2/1)11. Friction (3/1)12. static (3/1)13. sliding (3/1)14. wheel (3/1)15. strength (5/2)16. terminal velocity (4/2)17. inertia (6/3)

Part B. Concept Review (page 118)1. Static (3/1)2. either push or pull (1/1)3. friction (3/1)4. net force (1/1)5. motion (5/2)6. third (6/3)7. slow down (5/2)8. balanced (4/2)9. It is easy to miss an action-reaction pair whenone object is much more massive than another.Examples will vary. One example is a persontrying to push a space shuttle by hand. (6/3)10. Friction will never speed up an object because it always acts against the object’s direction of motion. (3/1)

ReinforcementSection 1 (page 119)1. d2. c3. a4. e5. b6. S (south)7. N (north); the filings between the poles of each magnet are repelled, so the poles must be like poles.8. North and south (or south and north); the filings between the poles of the two magnets areattracted, so the poles must be unlike poles.9. Use the filings to map the magnetic field around each magnet. The lines of force around the stronger magnet will be longer and closer together.

Section 2 (page 120)1. a magnetic field

2. The poles of the magnetic field would be reversed.3. It would be magnetized.4. An electromagnet; the magnetic field woulddisappear.5. an electric current; induction6. An electric motor converts electric power tomotion.7. In an electric motor, the field of a permanentmagnet moves a current-carrying wire.When thecurrent is reversed (as in alternating current), thewire spins.8. An electric generator converts motion to electric power.9. This action induces an electric current in the coil.

Directed Reading for Content MasteryOverview (page 121)1. electric current2. magnetic field3. iron bar4. electromagnet5. electrons6. field7. compass needle

Section 1 (page 122)1. S2. N3. A magnetic pole always repels like poles.4. A magnetic pole always attracts unlike poles.5. the poles6. iron7. Earth’s poles8. attraction9. magnetite10. domains

Sections 2 (page 123)1. d2. b3. g4. a5. f6. c7. e

8. converts electric energy into kinetic energy9. uses a magnetic field to turn motion intoelectricity10. changes the voltage of an alternating currentwith little loss of energy

Key Terms (page 124)1. magnetic domain2. magnetic field3. magnetism4. compass5. electromagnet6. electric motor7. aurora8. magnetosphere9. electric generator10. transformer11. alternating current

Chapter ReviewPart A. Vocabulary Review (page 125)1. magnetic domain (1/1)2. motor (5/2)3. electromagnet (4/2)4. aurora (4/2)5. generator (4/2)6. transformer (4/2)7. magnetic field (2/1)8. alternating (4/2)9. magnetosphere (1/3)

Part B. Concept Review (page 125)1. line up with north poles pointing toward themagnet (1/1)2. at the poles3. a magnetic field (1/1)4. the aurora (4/2)5. more coils of wire (4/2)6. an electromagnet (4/2)7. electricity (6/2)8. high voltage to low voltage (4/2)9. two times (5/2)10. south (1/1)11. atoms that release energy transferred to them by charged particles that enter theatmosphere (4/2)12. Alternating current changes direction many

times per second; direct current flows only inone direction. (5/2)13. It will be 10 times greater, or 1,200 V. (5/2)14. Move the coil through a magnetic field, or move a magnet into and out of the coil.15. The iron filings will line up along the magnetic field of the magnet. They will form a pattern of curved lines between the two poles.16. There is no definite edge. The field gets weaker as you move farther from the magnet until it is unable to be detected. (2/1)17. They are the groups of atoms with their magnetic fields all pointing in the same direction. They are found only in materials that can become magnetized. (1, 3/1)18. Yes; the magnetic pole has moved slightly over the years and the magnetic field has reversed direction multiple times. (3/1)

ReinforcementSection 1 (page 127)1. e2. a3. d4. b5. c6. It takes one year for Earth to revolve all the way around the Sun.7. The rotation of Earth on its axis causes nightand day.8. We have seasons because Earth’s axis is tilted.9. An eclipse happens when Earth, the Sun, andthe Moon are lined up in a certain way.10. The new moon and half moon are two of themoon phases.

Section 2 (page 128)Across3. asteroids4. smallest6. rings8. outer9. gravity10. third

11. meteorite

Down1. solarsystem2. comet5. largest7. sun12. red

Section 3 (page 129)1. A star’s color indicates its temperature. A red star is cool, a yellow star is medium in temperature, and a blue-white star is hot.2. A large star that begins to use up the fuel in itscore expands to become a supergiant. In time, itscore collapses, and the star explodes, becoming asupernova. The star’s core, if it’s not too large,becomes a neutron star. If the core is massiveenough, it could collapse and become a black hole.3. A medium-sized star that begins to use up thegases in its core gets bigger and becomes a giant.In time, it will shrink to a hot white dwarf andthen cool and become a black dwarf.4. Some galaxies are elliptical in shape, like a football. Others are spiral in shape, something like a pinwheel. Irregular galaxies come in all different kinds of shapes and are usually smaller than the other galaxies. The Milky Way, the galaxy we live in, is a spiral galaxy.5. The distances between galaxies are too large to measure in astronomical units so they aremeasured in light-years. A light-year is thedistance light travels in one year, 9.5 trillion km.6. Scientists think that stars begin as huge clouds of gas and dust. Gravity causes the dust and gases to move closer together. As they do, the temperatures in the cloud begin to rise, and the heat becomes great enough to cause the atoms in the

cloud to join together. This joining of atoms is called fusion, and it changes matter to the energy that powers the star.7. We live in the Milky Way, one of the billions of galaxies that make up the universe.

Directed Reading for Content MasteryOverview (page 131)1. Moon2. 27.3 days3. Earth4. 365 days5. Sun6. 225 million years7. Milky Way galaxy

Section 1 (page 132)1. new2. waxing3. waxing4. waxing5. full6. waning7. waning8. waning9. 27.3 days10. rotation11. winter12. a. Moon, Earth b. Earth, Moon

Sections 2 and 3 (page 133)1. elliptical; shaped like huge footballs or spheres; the most common type2. spiral; have arms radiating out from their center; kind of like a pinwheel3. irregular; come in different shapes; usuallysmaller; common4. solar system5. Sun6. constellation7. Milky Way8. spiral9. astronomical units

Key Terms (page 134)1. rotation2. revolution3. eclipse4. astronomical unit5. solar system

6. constellations7. light-year8. orbit9. supernova10. comet11. meteorites

Chapter ReviewPart A. Vocabulary Review (page 135)1. eclipse (3/1)2. solar system (4/2)3. rotation (1/1)4. revolution (1/1)5. constellation (7/3)6. galaxy (8/3)

Part B. Concept Review (page 135)1. Answers will vary, but should mention Earth’srotation and that the Sun’s light falls on only halfof Earth at one time. (2/1)2. Answers will vary, but should mention Earth’sannual revolution around the Sun, that Earth istilted at an angle on its axis in relation to the Sun, and that summer occurs on the part of Earth that is tilted toward the Sun while winter occurs on the part of Earth tilted away from the Sun. (1/1)3. Answers will vary, but should indicate that theMoon orbits Earth, or revolves around it. (2/1)4. Earth is in the Milky Way galaxy. There might be 100 billion galaxies. (7/3)5. Diagrams will vary. Check students’ diagrams for correct labeling. (3–5/2)