Reading in Science

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Where Can Water Be Found Lesson 1
Underground?

Look at the picture. Identify the path water takes to become groundwater.
Water Goes Underground

Rain

Soil Soil water
holding soil water Groundwater

Rock that
water can
pass between

Rock that
water cannot
pass between

Use the diagram above to fill in the blanks.

1. The two types of water below the ground are
and .

2. When rain falls to the ground, it is absorbed first by the . © Macmillan / McGraw - Hill

3. Water in the soil is called .

4. Water passes through the soil and into

.

5. Water stored in spaces and cracks of underground rock is called
.

6. Groundwater begins to accumulate when water reaches
.

186 Unit D · Water and Weather Use with textbook page D10

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How Much Water and Where? Lesson 1

The chart shows where water is found on Earth. It also tells how much water
is found in each place.

Oceans and seas Glaciers and ice caps
– About — About
97 of the total 2 of the total
100 100

water on Earth water on Earth

Soil water and groundwater;

lakes, ponds, rivers, and

˜ atmosphere; plants and
animals

About 1 of the total water
100

on Earth

Read the captions in the chart to answer these questions.

1. Fractions are ratios that compare a part of something to the whole of
something. In picture 2, what do the numbers 2 and 100 represent?

© Macmillan / McGraw - Hill 2. Where is most of Earth’s water found?
3. How much of Earth’s water is not found in the oceans and seas?

Unit D · Water and Weather Use with textbook page D11 187



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Water, Water Everywhere Lesson 1

Fill in the blanks.

1. The world’s hold almost all atmosphere
our water. glaciers
water vapor
2. Water in a gas state is called . water
oceans
3. Water is also found in the ice cap
that surrounds Earth. groundwater
soil water
4. Plants get water from .

5. At least half the weight of most plants and animals

is made up of .

6. A thick sheet of ice covering a large area of land is

called a(n) .

7. Some water does not move because it is frozen in
or ice caps.

8. Water stored in the cracks of underground rocks is .

Answer each question.
9. Where is water found as ice? Where is water found as water vapor?

© Macmillan / McGraw - Hill 10. What would you do if every person were only allowed to use 20 gallons
of water per day? How would your life change?

Unit D · Water and Weather Use with textbook pages D4–D13 189

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Water, Water Everywhere Lesson 1

groundwater oceans seas atmosphere
water vapor location soil water deserts

Fill in the blanks.

Most of Earth’s water can be found in and

. Water is also found in the in a

gas state known as . How much water

vapor there is in the atmosphere depends on the .

There is more water vapor over large bodies of water than over

or other dry areas. The water that soaks into soil

is called . Some of it is used by plants,

and some of it is stored in the cracks and spaces of underground rock

as .

© Macmillan / McGraw - Hill

190 Unit D · Water and Weather Use with textbook pages D4–D13

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Follow the Water Lesson 2

Fill in the blanks. Reading Skill: Sequence of Events - questions 9, 17, 26

What Makes Water Disappear?

1. Heat energy from the Sun causes water particles to .

2. The process in which water particles change from a liquid to a gas is

called .

3. Water vapor rises because it is than air.

4. Water vapor is a(n) gas.

5. Water evaporates from Earth’s and
.

6. High in the atmosphere, water vapor particles move
because it is cold.

7. These water vapor particles lose heat energy, slow down, and
.

8. Tiny droplets of condensed water in the atmosphere form
.

9. When clouds grow heavy with water droplets,
causes them to fall to the ground.

What Is Precipitation?

© Macmillan / McGraw - Hill 10. Rain, snow, hail, and sleet are forms of .

11. The form in which precipitation falls depends on .

12. Most precipitation falls into the .

13. Some water soaks into the ground as or
.

Unit D · Water and Weather Use with textbook pages D14–D23 191

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14. Cold temperatures cause water to release heat Lesson 2

energy, or lose heat, and the moving particles in water to slow down

and .

15. Warm temperatures cause water particles to absorb heat energy,

causing ice and snow to .

How Does Water Travel?

16. Water continually from place to place.

17. The never-ending movement of water through evaporation, .
condensation, and precipitation is called the

18. In Earth’s water cycle, the causes evaporation.

19. The oceans never overflow because water
from them.

20. Heat is released during .

21. Heat is absorbed during .

22. The source of energy for Earth’s water cycle is the .

What Kinds of Precipitation Do You Get?

23. Snowflakes are small , clear and shiny particles, of
ice.

24. Snow forms in air that is below .

25. Falling pieces of ice that are 5 millimeters or larger are called © Macmillan / McGraw - Hill
.

26. When rain falls through layers of cold air, the raindrops freeze to

form .

192 Unit D · Water and Weather Use with textbook pages D14–D23

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What Makes Water Disappear? Lesson 2

The diagram shows how the processes of evaporation and condensation
continuously move water between Earth’s surface and the atmosphere. Read
the captions from 1 to 5 to understand each process.

Evaporation and Condensation

– ˜Cold air makes water vapor
Heat energy from the Sun makes
water particles move quickly. particles move slowly. They
condense, or change from a
gas to a liquid.

™
Condensed water particles
form clouds.

—Water evaporates from Earth’s šWater droplets in clouds become

land and water surfaces. Water so heavy that they fall back to
vapor, an invisible gas, rises Earth.
because it is lighter than air.

Use the diagram to answer the questions.
1. Where does the water go when it evaporates?

© Macmillan / McGraw - Hill 2. What happens to the water vapor particles as they cool?
3. What causes rain to fall to Earth’s surface?

Unit D · Water and Weather Use with textbook pages D16–D17 193

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How Does Water Travel? Lesson 2

Look at the picture. Notice how arrows are used to show how water moves
from place to place in the water cycle. Because this is a cycle, you can start
anywhere on the diagram. If you follow the arrows, eventually you’ll get
back to where you started.

Water vapor condenses The Water Cycle
to form clouds of water
particles or ice particles. Precipitation occurs
over land and
oceans.

In Earth’s water Rivers carry millions Some water runs into
cycle, the Sun’s of liters of water into streams and rivers,
energy causes the oceans every day. and some seeps into
evaporation. the ground.
The oceans never
overflow because
water evaporates
from them.

Use the diagram above to fill in the blanks. .
1. Clouds are formed when water

2. As water changes from a liquid to water vapor, it .

3. Oceans never overflow because the causes
evaporation.
© Macmillan / McGraw - Hill
4. Condensed water falls to Earth as .

5. As precipitation falls to Earth, the water runs into the rivers so the rivers

can return it to the .

6. Clouds are made up of or .

7. The movement of water through evaporation, condensation, and

precipitation is called the .

194 Unit D · Water and Weather Use with textbook pages D20–D21

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How Does Water Travel? Lesson 2

Look at the diagram. Follow the arrows to see how water changes its state
when it absorbs or releases energy.

Transfer of Heat in the Water Cycle

Evaporation
(water vapor)

Heat is Heat is
released. absorbed.

Condensation Melting
(liquid water) (liquid water)

Heat is Heat is
released. absorbed.

Freezing
(solid water)

Use the diagram above to fill in the blanks.

© Macmillan / McGraw - Hill 1. Water may exist in three states: , and c. .
a. , b.

2. As water moves through the water cycle, it changes state as it
or energy.

3. Liquid water evaporates as heat is .

4. Water vapor condenses as heat is .

5. As heat is absorbed, ice .

6. As liquid water releases heat, it .

Unit D · Water and Weather Use with textbook page D21 195



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Follow the Water Lesson 2

Fill in the blanks. . evaporation
melt
1. At low temperatures liquid water can condensation
to become solid ice. precipitation

2. Water in the atmosphere falls to Earth as
.

3. The Sun’s energy causes

4. Tiny droplets of condensed water in the atmosphere clouds
evaporates
form . freeze

5. Ice particles that absorb heat energy
into liquid water.

6. The oceans never overflow because water
from them.

7. The process when a gas changes to a liquid is called .

Answer each question.

8. What is the water cycle? What happens during the water cycle? What
makes these things happen?

© Macmillan / McGraw - Hill 9. Precipitation can fall as rain, snow, sleet, and hail. What two things help
determine what type of precipitation will fall from clouds?

Unit D · Water and Weather Use with textbook pages D14–D23 197

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Follow the Water Lesson 2

solid melt liquid
temperature absorb heat energy

Fill in the blanks.

Depending on the , water in the atmosphere falls as

rain, snow, sleet, or hail. Cold temperatures slow down water particles,

causing them to release . If enough heat energy is

released, water freezes and the water particles change from a(n)

into a(n) . During warm tem-

peratures, water particles heat energy. When water

particles absorb enough heat energy, ice and snow .

© Macmillan / McGraw - Hill

198 Unit D · Water and Weather Use with textbook pages D14–D23

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Motions in the Oceans Lesson 3

Fill in the blanks. Reading Skill: Sequence of Events - questions 5, 20

What Makes the Ocean Move?

1. One way that water moves is in , large streams of
water that flow in the ocean.

2. Cold water is more , or heavier, than an equal
amount of warm water.

3. Deep ocean currents begin in regions, where the
water is very cold and salty.

4. Warm, less dense water is pushed up to the surface at the
, causing a current.

Wind and Surface Currents

5. When steady winds blow over the ocean, they move the ocean waters

in currents called .

6. Some surface currents move warm water from the .

7. In the Northern Hemisphere, surface currents move in a(n)
direction.

8. Large landmasses cause surface currents to .

What Ocean Motion Is Caused by Gravity?

© Macmillan / McGraw - Hill 9. Ocean tides are caused by the pull of between
Earth and the Moon and the Sun.

10. The pull of gravity on the side of Earth facing the Moon makes the

oceans bulge outward causing .

11. The ocean water doesn’t come up as far on the shore during
.

Unit D · Water and Weather Use with textbook pages D26–D35 199

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12. In most places, there are Lesson 3
high tides and low tides each day.

How Can We Use Tides?

13. In some coastal areas, people make the ocean water flow behind a dam

as the tide .

14. As the tide goes out, the trapped water is used to turn a
, which will power machinery and make electricity.

What Is a Wave?

15. An up-and-down movement of water is called a(n) .

16. The highest part of a wave is called the .

17. The lowest part of a wave is called the .

18. The distance from the crest of one wave to the crest of another wave is

called the .

How Does Water Move in Waves?

19. Waves move in the direction of the .

20. Water particles in a wave moves up and down in a
path.

21. First, a wave’s trough touches the ocean bottom, then the © Macmillan / McGraw - Hill
moves ahead, and finally the wave breaks on

the shore.

How Do Oceans Change Coastlines?

22. When waves move against the shore and wear away the land, it is

called .

23. The coastline is built up and moves out toward the ocean as a result
of .

24. Violent storms with strong winds and heavy rains are called
.

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What Makes the Ocean Move? Lesson 3

One way ocean water moves is in currents. Look at the key to see which
arrows represent the cold and warm currents. Follow the arrows on the map
to see the directions in which ocean currents move. The captions describe
how water density causes deep ocean currents.

© Macmillan / McGraw - Hill Use the map to answer the questions.
1. What type of ocean currents flow toward the poles?

2. Where do the cold water currents begin?

3. How is the density of warm water different from the density of cold water?

4. How does the difference in water density cause the ocean currents to
form?

Unit D · Water and Weather Use with textbook page D28 201

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What Ocean Motion Is Caused Lesson 3
by Gravity?

The diagram shows how the pull of gravity between the Earth and the Moon
and the Sun causes ocean tides. A tide table tells you when tides will occur.
The photographs show a high tide and a low tide in one area.

Highest and Lowest Tides

Sun
Moon

Earth

Tides for Two Days

August

High Tide Low Tide

A.M. P.M. A.M. P.M.

9:35 9:43 3:31 3:36

10:21 10:26 4:17 4:21

Use the diagram, table, and photographs to answer these questions. © Macmillan / McGraw - Hill
1. Why does the Moon’s gravity have more affect on Earth than the Sun’s
gravity?

2. What kind of tides do the bulges outward make?

3. When would you use a tide table?

202 Unit D · Water and Weather Use with textbook page D30

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How Does Water Move in Waves? Lesson 3

A wave is an up-and-down movement of water. As the wind blows across the
surface of the ocean, it sets particles of water in motion. That begins a series
of events that ends with a wave breaking on the shore. The diagram shows
the steps a wave goes through as it forms and moves to shore.

How Waves Form

Wind Breaker
Shore
Crest
Trough

© Macmillan / McGraw - Hill Ocean bottom
Answer these questions about the diagram above.

1. Wind causes particles of water to move in a circular path. How is that
circular movement different in different parts of the ocean?

2. What is the difference between a crest and a trough?

3. What events occur before a wave breaks on the shore?

Unit D · Water and Weather Use with textbook pages D33 203

© Macmillan / McGraw - Hill

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Motions in the Oceans Lesson 3

Read each statement. Write T if the statement is true. Write F if the
statement is false. Boldfaced words indicate new vocabularies.

1. Currents are large streams of water that flow in the ocean.

2. Hurricanes are storms with high winds and average rainfall.

3. The ocean tides are caused by the pull of gravity between Earth,
the Sun, and the Moon.

4. Surface currents move in circular patterns.

5. The crest is the lowest part of a wave.

6. Deep ocean currents flow where the water is very warm.

7. Currents in the Northern Hemisphere move in a clockwise
direction.

8. Waves on the ocean move in the direction of the wind.

9. The Moon’s orbit around Earth causes daily changes in the
ocean tides.

10. Erosion causes the coastline to move out toward the ocean.

Answer each question.
11. How do erosion and deposition affect a coastline?

© Macmillan / McGraw - Hill 12. How does gravity affect the tides of the ocean?

Unit D · Water and Weather Use with textbook pages D26–D35 205

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Motions in the Oceans Lesson 3

water levels gravity orbit high tide
gravity tides full new

Fill in the blanks.

The pull of between Earth and the Moon and Sun

causes . Tides are the rise and fall of ocean

. When the pull of gravity causes oceans to bulge

outward, there’s a(n) . Tide changes are also affected

by the Moon’s around Earth. Tides are higher and

lower than usual during and

Moons. During these times, the pull of is stronger.

© Macmillan / McGraw - Hill

206 Unit D · Water and Weather Use with textbook pages D26–D35

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Go with the Flow Lesson 4

Fill in the blanks. Reading Skill: Sequence of Events - questions 5, 21

How Fast Does Water Flow in Soil and Rocks?

1. Soil is made up of mixed with
decaying plant and animal material, water, and air.

2. The tiny spaces between particles of soil that let liquids and gases pass

through are called .

3. Water can soak into soil by the pull of gravity because it is
.

4. Water moves quickly through soils that have
pore spaces.

5. Water first passes through the soil and then into
below.

6. Water in underground rocks is called .

7. The upper area of groundwater is called the .

8. Precipitation that doesn’t evaporate or soak into the ground becomes
.

9. Factors that affect runoff are soil type and .

How Do Wells Work?

© Macmillan / McGraw - Hill 10. The most common way of getting water from the ground is digging
a(n) .

11. For a well to produce water, its bottom must be below the
.

12. In some wells, water rises to the surface on its own because of
in the underground rocks.

Unit D · Water and Weather Use with textbook pages D36–D45 207

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How Do Plants Move Water from the Ground? Lesson 4

13. Plants help move water from the soil and the ground into the
.

14. Through their plants soak up nutrients and water
from the soil.

15. The green material in a plant cell’s traps energy
from the Sun.

16. The plant’s food is made from a combination of water and
.

17. The process in which plants release water vapor into the air through tiny

pores in their leaves is known as .

What Are Droughts and Floods?

18. When there is no precipitation, a(n) may occur.

19. Droughts are more severe when temperatures are .

20. In hot temperatures, water particles absorb more heat energy, causing

them to move and quickly.

21. When it rains at the end of a drought, water cannot soak into the

hardened ground, creating a lot of .

22. When a flood occurs, water accumulates more rapidly than the soil
can .

23. Pore spaces may become filled when: , and © Macmillan / McGraw - Hill
a. .
b.

24. In an effort to control floods, people build and

raise .

208 Unit D · Water and Weather Use with textbook pages D36–D45

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How Fast Does Water Flow Lesson 4
in Soil and Rocks?

Look at the insets comparing clay with sandy soil. Notice that rain passes
through one kind of soil more than the other. Then look at the diagram of
how water travels through soil and rocks.

Soil Soil water Clay Sandy soil
Water table Porous rock
Pore spaces filled with groundwater

Nonporous
rock

Use the diagram above to fill in the blanks.

1. Clay has small pore spaces, so it is porous than
sandy soil.
© Macmillan / McGraw - Hill
2. Water passes through soil and into the beneath it.

3. The tiny spaces between the particles of soil are called .

4. The top area of groundwater is called the .

5. Water passes through porous rock until it reaches a layer of
.

6. Water in underground rocks is called .

Unit D · Water and Weather Use with textbook page D38 209

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How Do Wells Work? Lesson 4

This diagram shows how precipitation forms runoff and
groundwater. Notice the depth a well must have to be to get groundwater.

Getting Groundwater

Dry Precipitation
well Producing as rain, snow,
sleet, or hail
well
Runoff
Soil Evaporation
Soil water Water table Lake or as water vapor
Groundwater river
Porous Ocean
rock

Nonporous
rock

Use the diagram above to fill in the blanks.

1. The bottom of a producing well is below the level of the
.

2. Water on top of soil is called .

3. Some water soaks into the and travels © Macmillan / McGraw - Hill
underground.

4. The dry well does not extend deeply enough to get .

5. Groundwater is held in below the water table.

6. Water that flows to rivers, lakes, and oceans returns to the atmosphere
as .

210 Unit D · Water and Weather Use with textbook page D40

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How Do Plants Move Water Lesson 4
from the Ground?

Plants move water from the soil and ground into the atmosphere. Follow the
arrows in the diagram to see where the water moves. The circled inset shows
a close up of the plant’s cells. The captions explain the process.

Plants give off water
vapor through pores
in their leaves.

Plants take up soil
water through their
roots.

© Macmillan / McGraw - Hill Use the diagrams to answer the questions.
1. Which part of the plant absorbs water from the soil?
2. Name the part of the plant that carries water from the roots to the
leaves.
3. Name the part of the plant where water escapes into the air.

4. How is the water that is taken up from the soil different from the water
that is released through the pores in the leaves.

Unit D · Water and Weather Use with textbook page D41 211



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Go with the Flow Lesson 4

Fill in the blanks.

1. Tiny spaces between rock particles in the soil are pore spaces
drought
called . vegetation
runoff
2. Clay is less than sandy soil. porous
flood
3. Plants take in water from the soil and return it to water table
transpiration
the atmosphere through .

4. During a long period of time with little or no

precipitation, a(n) may occur.

5. The upper area of groundwater is called the
.

6. Runoff can be affected by the amount of in an area.

7. The precipitation that doesn’t evaporate or soak into the ground

becomes .

8. Building dams and raising riverbanks can help control the damage from
a(n) .

Answer each question.

9. It has not rained in your area for a month, and there is talk of a
drought. What could you do to help conserve water?

© Macmillan / McGraw - Hill 10. You live near a stream. What might cause your area to flood?

Unit D · Water and Weather Use with textbook pages D36–D45 213

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Go with the Flow Lesson 4

pumps well rises fresh water
pressure rock water table drops

Fill in the blanks.

Groundwater is an important source of .A

common way to get groundwater is to dig a(n) .A

producing well’s bottom must be below the .

Then the water can flow through the formations into

the well. The water table when there are heavy rains.

During periods of less rain, the water table . Some

wells need to bring water to the surface. Other wells

rise on their own because of in the

underground rocks.

© Macmillan / McGraw - Hill

214 Unit D · Water and Weather Use with textbook pages D36–D45

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Water Please! Lesson 5

Fill in the blanks. Reading Skill: Sequence of Events - question 12

How Much Fresh Water Is There?

1. Fresh water only makes up of
Earth’s water.

2. Humans can easily obtain only of Earth’s fresh
water supply.

3. Communities provide many services that require water, including:

a. ,

b. ,

c. .

4. In the United States, each person may directly use as much as
a day.

© Macmillan / McGraw - Hill 5. Some everyday water uses include: ,
a. ,
b. ,
c. ,
d. , and
e. .
f.

How Is Water Used in Farming and Industry?

6. In places where rainfall is low or irregular, water for growing crops is

supplied by .

7. Irrigation water can be distributed to growing crops by plowed ditches

called , pipes, or sprinklers.

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8. Some power plants use the energy of Lesson 5

from heated water to make electricity.

How Does Water Get Polluted?

9. The main sources of water pollution are wastes from .
a. , b. , and c.

10. Pesticides and fertilizers are carried with that
moves into the ground.

11. The water table under a landfill must be at least
deep.

How Is Water Cleaned?

12. Before water can be distributed, it must be made
for use.

13. The place where water is made clean and pure is called a(n)
.

14. The passing of a liquid through materials that remove impurities is

called .

What Happens to Used Water?

15. Water mixed with waste is .

16. Large pipes or channels that carry sewage to a sewage treatment plant

are called .

17. An underground tank in which sewage is broken down by bacteria is © Macmillan / McGraw - Hill

called a(n) .

How Can We Save Water?

18. The use of water-saving methods is called .

216 Unit D · Water and Weather Use with textbook pages D46–D55

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How Much Fresh Water Is There? Lesson 5

Look at the circle graph showing Earth’s water supply. Imagine that the circle
ᎏ1100ᎏ00
is divided into one-hundredths. The pieces of the circle should add up to .
The narrow piece of the circle shows how little of Earth’s water is fresh.

Imagine that narrow piece divided into tenths. Notice that the three
fractions add to ᎏ1100ᎏ .

Earth’s Freshwater Supply

Salt water Very deep Fresh water readily
97 groundwater available (rivers, lakes,
100 and groundwater)
2
Fresh water 1
3 10
10
100
Fresh water
not readily
available
(frozen in
glaciers and
ice caps)

7

10

Use the chart above to fill in the blanks. . .
1. Only about ᎏ130ᎏ0 of Earth’s water is , and c.
2. Readily available fresh water comes from
a. , b.

© Macmillan / McGraw - Hill 3. Only about of Earth’s fresh water is
readily available.

4. Very deep groundwater makes up about
of Earth’s freshwater.

5. About 97 percent of Earth’s water is

6. Fresh water that is not readily available can be found: , and
a. , b.
c. .

Unit D · Water and Weather Use with textbook page D48 217

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How Is Water Cleaned? Lesson 5

Look at the diagram of a water treatment plant. Follow the arrows to trace
the path water takes from its source to homes, offices, and factories.

Water Treatment Plant

Chemicals Chemical Settling Filtration
treatment basin reservoir
Screen
Supply

(river, lake,
groundwater)

Water is moved Trash Impurities Sand, gravel
to homes, offices, Chlorine
factories. Reservoir

Pump (Filtered
water)
Homes

Use the diagram above to fill in the blanks. , and
1. The water supply comes from
a. , b.
c. .

2. Trash is removed from water by a(n) .

3. Before water travels to a settling basin, it is treated with . © Macmillan / McGraw - Hill
.
4. In the settling basin, most sink to the bottom.

5. In the , water is filtered through sand and

gravel to remove impurities.

6. Filtered water is treated with to kill any
remaining bacteria.

7. Water is moved to homes, offices, and factories using

218 Unit D · Water and Weather Use with textbook page D52

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Water Please! Lesson 5

Fill in the blanks.

1. Water suitable for human use is found in rivers, glaciers
sewers
lakes, and . pesticides
groundwater
2. The use of water-saving methods is called filtration
. water
conservation
3. Fresh water found in is not sewage
readily available for our use. irrigation
water
4. A place where water is made clean and pure is a(n) treatment
. plant
septic tanks
5. Farmers sometimes get water to their crops

through .

6. Rivers and streams may be polluted
by .

7. Large pipes or channels that carry sewage to a sewage treatment plant

are called .

8. Many impurities in water can be removed by .

9. Water mixed with waste is .

10. Areas with no public disposal systems have .

© Macmillan / McGraw - Hill Answer each question.
11. How can groundwater become polluted from a landfill?

12. What is the one thing you do frequently that uses the most water? How
can you conserve this water or cut back on your usage?

Unit D · Water and Weather Use with textbook pages D46–D55 219

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Water Please! Lesson 5

basin water chemicals screen
water treatment plant filtration impurities government

Fill in the blanks.

Before can be distributed to homes, it must be

made safe for use. This means, meeting safe drinking-water rules set by

the . The place where water is made clean and pure

is called a . At the plant water first passes

through a to remove animals, plants, and trash.

Then, various are mixed with water in a mixing

basin. The chemicals remove and kill harmful

bacteria. From there water moves to a settling

where most other impurities sink. Any impurities that are left are

removed by , the passing of liquid through materials

that remove impurities.

© Macmillan / McGraw - Hill

220 Unit D · Water and Weather Use with textbook pages D46–D55

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Earth’s Water Chapter 8

Circle the letter of the best answer.

1. In the atmosphere, water is in a gas state and is called

a. air. b. ice.

c. water vapor. d. puddle.

2. Water stored in the cracks and spaces of underground rock is called

a. atmosphere. b. vapor.

c. salt water. d. groundwater.

3. Condensed water droplets in the atmosphere form

a. rain. b. clouds.

c. sleet. d. snow.

4. When water particles change from a liquid to a gas, it is known as the

process of

a. evaporation. b. condensation.

c. irrigation. d. precipitation.

5. Water that soaks into the soil is called

a. groundwater. b. ice caps.

c. soil water. d. glaciers.

6. The least amount of Earth’s water is found in

© Macmillan / McGraw - Hill a. oceans and seas. b. soil, groundwater, lakes, and rivers.

c. glaciers and ice caps. d. north of the equator

7. Precipitation that does not evaporate or soak into the soil is

a. runoff. b. rain.

c. flood. d. ice.

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Circle the letter of the best answer. Chapter 8

8. Which is NOT a part of the water cycle?

a. evaporation b. condensation

c. precipitation d. melting

9. Precipitation in the form of very small pieces of ice is

a. sleet. b. rain.

c. cloud. d. snow.

10. Deep ocean currents occur where the water is

a. salty. b. cold.

c. warm. d. fresh.

11. Tides are caused by the gravity pull between
a. Earth and the Moon.
b. Earth and the Sun.
c. Earth, the Sun, and the Moon.
d. the Sun and the Moon.

12. An up-and-down movement of water is a

a. tide. b. current.

c. deep current. d. wave.

13. Water mixed with waste is b. sludge. © Macmillan / McGraw - Hill
a. sewer. d. slime.
c. sewage.

14. Which is NOT a cause of water pollution?

a. fish b. fertilizers

c. pesticides d. bacteria

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Chapter Summary

1. What are two vocabulary words you learned in the chapter?
Write a definition for each.

2. Which photograph, diagram, or illustration in the chapter best described
an idea?

3. What are two main ideas that you learned in this chapter?

© Macmillan / McGraw - Hill

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Earth’s Weather Chapter 9

You have learned how Earth’s water affects life on Earth.
Like water, air is necessary for life. Though water is a liquid and air is a gas,
both contain life-giving oxygen. Air is similar to water in other ways, too.
The particles of air are farther apart than water particles, but they are
affected by gravity just as water is. That is why the layer of air closest to the
ground is denser and has more pressure than the layers higher in the atmos-
phere. Just as warm and cold areas in the oceans interact to cause currents
that affect temperature and weather, air masses of different temperatures
result in strong winds and weather fronts. You could say that air and water
are the most important substances on Earth!

Think about the ideas in the passage and the other things you know about
air and water. How are air and water alike? How are they different? Record
your ideas in the Venn diagram.

Air Water

© Macmillan / McGraw - Hill

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Compare and Contrast Chapter 9

When you compare things, you look for similarities. When you contrast
things, you identify differences between them. Many things in nature are
alike in some ways, but different in others.

Sunrise and sunset are alike because they involve the position of Earth and
the Sun and each occurs once a day. But sunset and sunrise are different,
too. One occurs at the beginning of the day and brings the Sun into view,
and the other occurs at the end of the day as the Sun disappears from view.

Think about each pair of objects or events below. Then write at least one
way they’re alike and one way they’re different.

Alike Different

1. Snow and rain

2. The Moon and the Sun

© Macmillan / McGraw - Hill 3. A lake and an ocean
4. A flood and a tornado
5. A drought and a wildfire

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More Alike than Different? Chapter 9

Read the following descriptions of three climate zones in the United States.
Complete the chart by marking with X the features that apply to each kind
of storm.

In New England, winters are cold and snowy. Summers are fairly
hot and humid with frequent thunderstorms.

In the Southwest, winters are mild and dry and summers are warm
and dry. The desert areas are extremely hot.

In the Midwest, winters are usually cold and some areas receive
heavy rain or snow. Midwestern summers are hot and humid.

New England Southwest Midwest

cold winters
mild winters
snow
dry climate
warm or hot, humid
summers
rainstorms
hot, dry summers

Explain which two of the climate zones are the most alike and why. © Macmillan / McGraw - Hill

226 Unit D · Water and Weather Use with textbook pages D60–D93

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Air, Wind, and the Atmosphere Lesson 6

Fill in the blanks. Reading Skill: Compare and Contrast - questions 4, 5, 8,
10, 13, 14

What Is the Atmosphere?

1. Air is a (n) of gases.

2. The blanket of air surrounding Earth is called the .

3. Earth’s atmosphere has different layers.

4. The outer layer of the atmosphere has much air
particles than the layer closest to Earth.

5. The is colder than all the other layers of
the atmosphere.

What Makes Weather?

6. To describe weather, scientists measure these four properties of air:
a. ,
b. ,
c. , and
d. .

7. Humidity is a measurement of how much is in
the air.

© Macmillan / McGraw - Hill 8. When the weather is humid, the air feels hot and sticky. On cold autumn

days, the air is .

9. The force of air pushing on an area is called .

10. Cool air has air pressure than warm air.

11. Air in motion is called .

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What Makes the Wind Blow? Lesson 6

12. Wind is caused by uneven of Earth.

13. Dark surfaces absorb heat than light-colored surfaces.

14. Cool air particles are together than warm
air particles.

15. Air moves from a place of pressure to one of
pressure.

16. When air pressures over a region change, it causes the
to change direction.

Why Do Clouds Form?

17. When water vapor cools enough, it to form
water droplets.

18. Millions of tiny water droplets can join to form .

19. Stratus clouds form in .

20. Puffy clouds appear to rise from a flat bottom.

21. Wispy clouds are made of ice crystals.

How Can You Describe Weather?

22. A(n) measures air temperature.

23. A(n) measures air pressure. © Macmillan / McGraw - Hill

24. Wind speed is measured by a(n) .

25. A(n) shows wind direction.

26. A(n) tells how much rain has fallen.

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What Is the Atmosphere? Lesson 6

It is hard to imagine, but every breath you take contains millions of particles.
Air is made up of tiny particles of different gases. The mixture does not con-
tain the same amount of each gas. There is more of some gases and less of
others. Study the graph to find out more about the gases that make up air.

Oxygen 21%

other gases (carbon
dioxide, water vapor,
and others) 1%

© Macmillan / McGraw - Hill Nitrogen 78%

The Atmosphere
Answer these questions about the pie graph above.

1. What gas is more common than any other in Earth’s atmosphere? What
part of the air does it make up?

2. What is the second most common gas in Earth’s atmosphere? What part
of the air does it make up?

3. What gas that is important to plants makes up less than 1/100 of
the atmosphere?

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Earth’s Atmosphere Lesson 6

Earth is wrapped in layers of air particles. The layer of air that is familiar to
us is the one closest to Earth. Outside that layer are other layers that are
quite different from the one we know. Study the diagram to see how the
layers change as they get farther from Earth’s surface.

Layers of Earth’s Atmosphere

700 km
4 Thermosphere: temperatures rise

the higher you go.

3 Mesosphere: temperatures get 80 km
colder in this layer.
-90˚C (-130˚F)

2 Stratosphere: temperatures get 48 km
warmer as you go 18 km
higher -50˚ C to
nearly 0˚C

1 Troposphere: weather forms here

0 km

Answer these questions about the diagram above.
1. Which layer of the atmosphere is closest to Earth?

2. Which is the coldest layer of the atmosphere?

3. Which is the warmest layer of the atmosphere?
4. In what layer(s) of the atmosphere does weather form?

5. Why is life found only in the troposphere? © Macmillan / McGraw - Hill

230 Unit D · Water and Weather Use with textbook page D65

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Air, Wind, and the Atmosphere Lesson 6

Fill in the blanks.

1. A puffy cloud that appears to rise from a flat atmosphere
humidity
bottom is a(n) . air pressure
stratus cloud
2. A cloud that forms layers with other flat, clouds is cumulus cloud
a(n) . cirrus cloud

3. A wispy, feathery cloud is a .

4. When scientists measure how much water vapor is in

the air, they are measuring .

5. The blanket of air that surrounds Earth is called the .

6. The force of air pushing on an area is .

Answer each question.

7. How are the particles of cool air spaced compared to particles of warm
air?

8. Why is there wind on Earth?

© Macmillan / McGraw - Hill

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Air, Wind, and the Atmosphere Lesson 6

direction humidity wind troposphere
pressure atmosphere temperature speed

Fill in the blanks.

Living things depend on the gases in Earth’s . Four

air layers surround Earth. Weather forms in the layer closest to Earth’s

surface, which is called the . Scientists describe

weather by measuring four things about the air. A thermometer is

used to measure the air’s . A measurement of

how much water vapor is in the air is .A

barometer is used to measure air . Air in motion

is called . An anemometer is used to measure a

wind’s , and a weather vane is used to measure its

.

© Macmillan / McGraw - Hill

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Weather and Climate Lesson 7

Fill in the blanks. Reading Skill: Compare and Contrast - questions 3, 10,
11, 14

What Are Air Masses?

1. Large areas of air with nearly the same and
are called air masses.

2. Most air masses form in the and .

3. An air mass that forms near the North Pole will be colder and
than an air mass that forms in the tropics.

4. Air masses are always .

What Happens When Air Masses Meet?

5. The boundary between two air masses that have different

temperatures is called a .

6. Fronts usually bring a change in .

7. A front occurs when a warm air mass pushes into a
cold air mass.

8. A cold front occurs when a air mass pushes into a
air mass.

9. The weather that a cold front often brings can be .

© Macmillan / McGraw - Hill 10. Cold fronts move than warm fronts.

11. Unlike other fronts, a(n) front doesn’t move.

How Do Weather Maps Help Predict the Weather?

12. Weather maps show:

a. , b. , and

c. .

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13. In places where a warm front is passing through, Lesson 7

you can predict a light, steady .

What Is Climate?

14. Weather describes the atmosphere’s daily condition in an area, but
describes an area’s average weather over a long

period of time.

15. Important features of climate are average ,
, , and .

16. The United States is divided into climate zones.

What Affects Climate?

17. Climate is affected by:

a. , b. ,

c. , d. ,

e. , and f. .

18. The measure of how far north or south a place is from the equator is

called .

19. The measure of how high a place is above sea level is called
.

20. Winds that circle the globe and never stop blowing are called © Macmillan / McGraw - Hill
winds.

How Do People Change Climate?

21. The is caused by carbon dioxide and gases in

the atmosphere trapping solar energy near Earth’s surface.

22. By adding too much to the atmosphere, peo-
ple are increasing the greenhouse effect.

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What Are Air Masses? Lesson 7

Air masses are very large regions of air that have the same weather. The map
shows where the six major air masses form that affect the United States. The
arrows show how these air masses move.

Cold, dry
air mass

Cold, moist Cold, moist
air mass air mass
Warm, moist
Warm, air mass
moist
air mass Warm, dry
air mass

Use the map to answer the questions.
1. Describe the air mass that forms over the northern Pacific Ocean

2. How do the air masses that form in the north affect the United States?

© Macmillan / McGraw - Hill 3. How does the air mass that forms over land in the south affect the south
central United States?

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