Answer Key
Chapter 1 Test Answers
Multiple Choice
1. c / 2. d / 3. b / 4. c / 5. a / 6. c7. c / 8. b / 9. a / 10. d / 11. b / 12. a
13. a / 14. c / 15. b / 16. b / 17. c / 18. d
19. a / 20. b
Completion
1. Earth 2. nebular 3. geosphere 4. asthenosphere
5. constructive 6. latitude 7. Mercator 8. elevation
9. subsystems 10. system 11. sun 12. water
13. renewable 14. theory 15. hypothesis
Short Answer
1.The core is the densest and heaviest part. The
mantle, as a whole, is less dense than the core. The
lower mantle contains rigid rock. The upper mantle is
partially molten and makes up the asthenosphere.
Together they make up the lithosphere.
2.Remote sensing is the process in which data about
Earth is collected by something that is far away, such as
an orbiting satellite. Computers convert this data into
maps.
3.The world population was approximately 250 million
from 4000 B.C. to 2000 B.C.
4.Today there are about 5,850,000,000 more people
inhabiting the world.
5.As the population grows, consumption of resources
increases. Consumption of natural resources in the year
4000 B.C. would have been much less than it is today.
6.Sample answers: People burn gasoline and coal,
dispose of waste, clear land, and build breakwaters.
7.The process that forms oil, natural gas, and coal
takes millions of years. Since the process is so slow,
these resources are considered nonrenewable. Water
and wind are constantly being recycled. Their supplies
will not run out.
Essay
1.Clearing forests, building cities, constructing dams,
and other construction can change the size and
frequency of floods and landslides. The negative effects
of a hurricane, tornado, or tidal wave can end up being
much greater because of construction that alters the
land. In general, human activities that alter the land tend
to increase the destructive effects of natural hazards.
Chapter 2 Test Answers
Multiple Choice
1. b / 2. a / 3. b / 4. d / 5. c / 6. d7. b / 8. d / 9. a / 10. c / 11. b / 12. a
13. b / 14. b / 15. b / 16. c / 17. c / 18. d
19. b / 20. a
Completion
1. elements 2. eight, eight 3. negative 4. protons,
neutrons 5. electrons 6. molecule 7. covalent
8. hydrothermal 9. silicate 10. oxygen 11. halides,
sulfates and sulfides 12. luster 13. mass 14. sulfur
15. elements, structure
Short Answer
1.Both atoms have six protons. Carbon-12 has six
neutrons, while carbon-13 has 7 neutrons.
2. In an ionic bond, two ions are held together by
opposite charges. In a covalent bond, atoms are held
together by sharing electrons. Metallic bonds form
when metallic ions share electrons.
3.It must be naturally occurring, a solid within Earth’s
normal temperature range, a substance with an orderly
crystalline structure, have a definite chemical
composition, and be considered inorganic.
4.Increased pressure can rearrange the crystalline
structure of a mineral, changing it to another more
compact mineral. Temperature changes can make a
mineral unstable and result in the formation of a new
mineral that is stable at the new temperature.
5.They are a group of minerals that contain carbon,
oxygen, and one or more other metallic elements;
calcite and dolomite
6.Any three: color, a streak, crystal form, hardness,
density, whether the mineral breaks with cleavage or
fracture
7.The color of a mineral can vary from sample to
sample, but the color of a mineral’s streak remains
constant from sample to sample.
8.It has transferred to the chlorine atom.
9.It has gained an additional negatively charged
electron.
10. It is an ionic bond.
11.It is a silicon-oxygen tetrahedron.
12.It has four oxygen atoms and one silicon atom.
13.It is between 7 and 8.
14.Diamond, because it’s the only material harder than
all the minerals listed.
Essay
1.The extraction of minerals from the ground through
mining and drilling disturbs Earth’s surface, causing the
destruction of natural vegetation, soil erosion, and
pollution. Earth’s atmosphere and hydrosphere can
be polluted by factories that refine and process
minerals and release waste products into nearby waters
or air.
Chapter 3 Test Answers
Multiple Choice
1. d / 2. c / 3. a / 4. b / 5. b / 6. b7. a / 8. c / 9. c / 10. b / 11. d / 12. a
13. c / 14. c / 15. a / 16. b / 17. c / 18. a
19. b / 20. c
Completion
1. rock 2. sedimentary 3. rock cycle 4. Igneous
5. heat 6. magma 7. lava 8. coarse-grained
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9. ultramafic 10. intrusive 11. glassy 12. Basaltic
13. smallest 14. chemical 15. regional
Short Answer
1.Both are types of rocks formed as a result of the rock
cycle. Both types of rock can form from the other type.
They differ in the way they form. Metamorphic rocks
form as a result of intense heat and pressure.
Sedimentary rocks form as a result of cementation and
compaction.
2.Heat causes recrystallization or new minerals to form.
Pressure causes compaction and recrystallization.
Hydrothermal solutions cause recrystallization and an
overall change in composition.
3.If the rock is undisturbed, the fossils in layer B are
probably older than those found in layer C.
4. If the rock is undisturbed, the fossils in layer B are
probably younger than those found in layer A.
5.Marble is a nonfoliated metamorphic rock. Gneiss is
a foliated metamorphic rock.
6.Silicates require higher temperatures in order for
metamorphosis to occur.
Essay
1.An igneous rock forms when magma or lava cools.
Over time, the igneous rock is broken down into smaller
and smaller pieces, or sediments. The sediments
become compacted and cemented together as more
time passes and a sedimentary rock is formed. If the
sedimentary rock is subjected to intense heat and
pressure, it can form a metamorphic rock. The
metamorphic rock can become an igneous rock again if
it becomes buried deep beneath Earth’s surface and
melts into magma.
Chapter 4 Test Answers
Multiple Choice
1. d / 2. a / 3. c / 4. b / 5. d / 6. b7. c / 8. a / 9. c / 10. d / 11. a / 12. d
13. d / 14. b / 15. d / 16. c / 17. b / 18. c
19. a / 20. c
Completion
1. nonrenewable 2. tar sand 3. oil shale 4. igneous,
hydrothermal 5. building, industrial 6. energy
7. sediment 8. nitrogen 9. fossil 10. acid 11. Clean
Water 12. Clean Air 13. selective 14. sanitary
Short Answer
1.Renewable resources can be replaced within a short
time period such as years, months, or decades. It takes
millions of years to replace nonrenewable resources, so
their supplies are considered finite.
2.Formation begins when ocean sediment buries the
remains of plants and animals. Over millions of years,
with the remains cut off from oxidation and decay,
chemical reactions gradually transform the plants and
animals into petroleum and natural gas.
3.Uranium-235 atoms are bombarded with neutrons.
The uranium nuclei split into smaller nuclei and emit
neutrons and energy. The reaction continues with
additional atoms, creating a chain reaction that
produces a great deal of heat. The heat is used to
create steam that drives a turbine that turns an electrical
generator.
4.The advantages are that the power source is free and
nonpolluting. The disadvantages are that wind is noisy
and there is need for lots of land.
5.A dam is constructed across the mouth of a bay or
an estuary with a large tidal range. Water flows through
the dam and into the enclosed area behind it at high
tide. At low tide, the water trapped behind the dam
(which is now at a higher level than water outside the
dam) flows out and down through the dam to turn a
turbine and generate electric power.
6.There are carbon monoxide and sulfur oxides.
7.Motor vehicles are the biggest source of air pollution.
8.People and animals need the atmosphere’s oxygen
to live. Other substances in the atmosphere, such as
carbon, are also essential for life. Ozone protects Earth
from harmful solar radiation. Greenhouse gases help
maintain Earth’s atmosphere.
9.They show the decrease in the area of virgin forest
between 1620 and 1998.
10.The West has maintained the largest percentage.
11.Individuals can conserve wood products, such as
paper, by recycling and consuming fewer wood
products.
Essay
1.Energy conservation saves land and mineral
resources, which means less mining that can disturb
and poison land and less cutting of forests that can
increase soil erosion. Energy conservation means less
production of energy and less manufacturing of
products, which cut down on air pollution. The need for
fewer products and for less mining and logging
produces less waste that could end up in surface and
underground waters.
Chapter 5 Test Answers
Multiple Choice
1. b / 2. c / 3. d / 4. a / 5. a / 6. d7. b / 8. d / 9. b / 10. a / 11. b / 12. d
13. c / 14. a / 15. d / 16. d / 17. a / 18. b
19. d / 20. b
Completion
1. mechanical weathering 2. carbonic acid
3. Differential 4. carbon dioxide 5. loamy
6. microorganisms 7. plant growth 8. Hardpan
9. deepest 10. pedocal 11. logging 12. mass
movement 13. water 14. earthquake 15. Creep
Short Answer
1.Mechanical weathering breaks up rock into smaller
pieces. This exposes more surfaces of the rock and
makes it easier for chemical weathering to occur. A rock
that is broken up into pieces by frost wedging, for
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example, has more areas exposed to chemical
weathering agents. A rock that remains in one piece has
fewer exposed surface areas and will weather more
slowly.
2.The A horizon contains topsoil and is made up
mostly of organic matter. The B horizon contains subsoil
and is made up mostly of clay from the A horizon. The
C horizon is made up of partially weathered parent
material.
3.The layer below the C horizon is made up of
unweathered parent material.
4.Laterite soils have a high concentration of bacteria,
which helps to decompose decaying plants and
animals. Because of this high bacterial activity in laterite
soil, plants and animals there decompose very quickly.
This leaves very little organic matter in the soil.
5.The garden would grow better in Tennessee because
the pedalfer soil that is characteristic of the area is
higher in organic matter and nutrients than the laterite
soils found in tropical rainforests.
6. A forest fire increases the probability of a mass
movement. The fire destroys vegetation that binds the
soil and regolith together. Without the vegetation, the
soil becomes unstable, and the likelihood of mass
movement increases.
Essay
1.Surface rocks are weathered by water, wind, animals,
ice, and temperature changes. As these rocks weather,
particles and sediment are carried by wind and water to
other places. As these rock bits build up, they add to
the topsoil. Below Earth’s surface, bedrock is
weathered by pressure and temperature. As this
happens, the weathered bedrock adds sediment and
rock particles to the soil layers above it.
Chapter 6 Test Answers
Multiple Choice
1. b / 2. a / 3. c / 4. d / 5. a / 6. d7. c / 8. b / 9. c / 10. a / 11. a / 12. c
13. c / 14. d / 15. b / 16. b / 17. a / 18. d
19. b / 20. a
Completion
1. sun 2. oceans 3. glaciers 4. 0.62 5. oceans, land or
continents 6. gradient, discharge 7. channel
8. discharge 9. grinding 10. dissolved 11. meanders
12. capacity 13. oxbow lake 14. meander
15. floodplains 16. flooding 17. divide 18. geyser
19. artesian 20. “hard” 21. aeration
Short Answer
1.Energy from the sun evaporates water from
Earth’s surface. As the moist air rises, it cools and
condenses into cloud droplets. Precipitation then falls
from the clouds to the ground, where the cycle begins
again with evaporation of water from land and surface
waters.
2.The cross-sectional view of a stream shows that the
stream’s gradient decreases between its source and its
mouth.
3.The uplift causes the river to rise higher above its
base level. So the river resumes downcutting its
channel to reach its new base level.
4.Deposition occurs when a stream has less ability to
carry sediment because its velocity has decreased. As a
result, the sediment begins to settle out.
5.Any flood occurs when the discharge of a stream
exceeds the capacity of its stream channel. But a flash
flood occurs over a smaller area than a flood, often
occurs with little warning, and can therefore be deadly.
6.Groundwater moves by twisting and turning through
the interconnected small openings in rock and soil.
7.Groundwater is nonrenewable because supplies are
finite, and it could take thousands of years to replenish
water that is being rapidly withdrawn in some areas.
8.Stalactites are icicle-like stone pendants that form as
water containing minerals drips from cavern ceilings.
Stalagmites are formations that develop when mineralrich
water drops on a cavern floor, and large features
build up from the floor and reach toward the ceiling.
Essay
1.The fewer structures there are along the river
floodplain, the less damage there would be from
flooding. As a result, building a commercial center with
stores and offices would be a mistake, because these
buildings would be damaged during each flood. The
park and ball field are the wiser choices. They would
allow the river to expand over its floodplain during a
flood without damaging structures.
Chapter 7 Test Answers
Multiple Choice
1. b / 2. c / 3. c / 4. d / 5. a / 6. d7. c / 8. c / 9. b / 10. a / 11. c / 12. b
13. d / 14. b / 15. a / 16. d / 17. c / 18. b
19. d / 20. b
Completion
1. valley glaciers 2. ice sheets 3. accumulation
4. abrasion 5. glacial trough 6. Stratified drift
7. outwash plain 8. Great 9. ephemeral 10. alluvial fan
11. deflation 12. abrasion 13. loess 14. windward,
sheltered 15. transverse 16. A. barchan, B. transverse,
C. barchanoid, D. longitudinal
Short Answer
1.Both are types of glaciers. Valley glaciers exist in high
mountains and flow down valleys. Ice sheets are huge
ice masses that flow in all directions. There are only two
ice sheets on Earth—one in Greenland and one in
Antarctica.
2.There is little vegetation in the desert, so rain runs off
the land quickly, causing flash flooding. Also, the lack of
vegetations means that the soil is loose and erodes
quickly and easily.
3.The vegetation acts as an obstruction to the blowing
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sand and changes the way the sand is deposited.
All dunes begin because of some obstruction that
causes the wind to slow and the sand it is carrying
to drop.
4.Hanging valleys form when a glacier recedes. The
valleys of the smaller side glaciers are left at a higher
level than the main glacial trough.
5.Cirques are formed where snow and ice accumulate
at the head of a valley glacier. They are bowl-shaped
depressions surrounded on three sides by steep rock
walls.
Essay
1.The wind’s velocity falls when it encounters an
obstruction, and the sand particles it carries drop to the
ground. A dune begins near an obstruction, but once
the mount builds, it serves as its own obstruction and
traps more and more sand. The wind blows up and
over the crest of the dune on the windward side. The
wind speed slows abruptly at the crest, and the sand
drops down on the sheltered side of the dune.
Chapter 8 Test Answers
Multiple Choice
1. b / 2. a / 3. c / 4. d / 5. b / 6. d7. b / 8. a / 9. c / 10. b / 11. c / 12. c
13. b / 14. a / 15. c / 16. a / 17. c / 18. d
19. b / 20. b
Completion
1. focus 2. rebound 3. aftershocks 4. surface, body
5. intensity, magnitude 6. energy, fault 7. 3.9 8. 8.0
9. Pacific 10. fires 11. seismic 12. mantle
13. asthenosphere 14. liquid 15. bend
Short Answer
1.Rock along a fault line bends as stress is put on it.
When stress reaches a high enough level, the rock slips
or breaks along the fault. This releases stored energy as
seismic waves.
2.P waves compress and expand material through
which they pass and create a back-and-forth motion
along the surface that makes the ground buckle and
crack. S waves shake material at right angles to their
direction of motion, making the ground shake up-anddown
and sideways. One type of surface wave moves
the ground from side-to-side, while another type moves
along the surface like rolling ocean waves.
3.On a map, draw a circle around each seismic station
that represents the distance of the epicenter from each
station. The point where the three circles intersect is the
epicenter.
4.Factors include the intensity and duration of the
vibrations, the nature of the material on which structures
are built, and the design of structures.
5.Yes; they can use historical records and measuring
devices and study seismic gaps. However, the
predictions are only estimates.
6.Scientists assume that meteorites are made of the
original material from which Earth formed, so they can
provide clues to Earth’s early composition as compared
with today.
7.The model shows Earth’s layers based on chemical
composition. A: inner core, B: outer core, C: mantle, D:
crust.
8.They change direction when they pass through areas
of different composition or density.
Essay
1.The movement of plates on the ocean floor can
cause a tsunami, sending a huge tidal wave onto
shorelines. The wave can cause or worsen erosion of
coastal features such as beaches and cliffs. It could
also destroy human-made structures at or near the
coast.
Chapter 9 Test Answers
Multiple Choice
1. c / 2. b / 3. d / 4. a / 5. a / 6. c7. a / 8. d / 9. a / 10. b / 11. c / 12. c
13. c / 14. b / 15. b / 16. d / 17. d / 18. c
19. d / 20. b
Completion
1. Pangaea 2. coastlines 3. mountain belts 4. glacial
till 5. A: North America; B: Eurasia; C: South America;
D: Africa; E: India; F: Antarctica; G: Australia 6. magma
7. oceanic 8. Pacific 9. Trenches, volcanoes, and
mountain ranges 10. divergent boundary 11. seafloor
12. convergent 13. volcanic island arc
14. asthenosphere 15. convection 16. slab-pull
17. volcanoes
Short Answer
1.About 200 million years ago, the supercontinent
called Pangaea broke up into smaller continents that
began drifting to their present positions.
2.The East African Rift valley represents the spreading
that is occurring at a diverging plate boundary. In the
future, the rift valley will continue to spread and will
ultimately become an ocean basin.
3.Both are convergent boundaries and involve
subduction of oceanic lithosphere. The oceanic-oceanic
boundary creates volcanic activity. The continental-
continentalboundary creates mountain ranges.
4.The whole-mantle convection model states that hot
mantle plumes containing material from different depths
move heat toward the surface.
Essay
1.Seafloor spreading occurs at divergent plate
boundaries. Magma rises and forces crust upward. This
causes pieces of the continental crust to crack and pull
apart. Some slabs of the crust sink, causing a rift zone.
If the lithosphere continues to spread, a narrow sea can
form. Continued spreading produces an ocean basin
and ridge system.