3 5 follow a raindrop (earth science)

Genre

Nonfiction

Comprehension Skill

Cause and Effect

Text Features

•
•
•
•

Captions
Text Boxes
Diagram
Glossary

Science Content

Water

Scott Foresman Science 3.5

ISBN 0-328-13822-3

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Vocabulary

Extended Vocabulary

condensation
evaporation
groundwater
precipitation
water cycle
water vapor
wetlands

atmosphere
classify
molecule
natural disaster
perspiration
saturation
transpiration

Picture Credits
Every effort has been made to secure permission and provide appropriate credit for photographic material.
The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).
Opener: Bruce Peebles/Corbis; 5 Bruce Peebles/Corbis; 6 (B) Color Box/ImageState; 10 (BR) Jose Luis Pelaez, Inc./Corbis;
11 Marc Muench/Getty Images; 12 (B) ©J. B. Pickering/Eye Ubiquitous; 13 Harolod Palo Jr./NHPA Limited.
Scott Foresman/Dorling Kindersley would also like to thank: 7 NASA/DK Images.
Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson.

ISBN: 0-328-13822-3

Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America.
This publication is protected by Copyright, and permission should be obtained from the publisher prior to any
prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,
mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to
Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.
3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05

What did you learn?
1. How are raindrops formed?
2. Why is rain important?
3. How big are raindrops?
4.

Every single
raindrop is part of the water cycle.
Write to explain how a raindrop
by L.L. Owens
travels through the water cycle.
Include details from the book to
support your answer.

5.

Cause and Effect When water
vapor condenses and turns to liquid
high up in the atmosphere, what is
the effect?


What You Already Know

Water is everywhere, and it is constantly
changing form. Rain, snow, sleet, and hail are all
forms of water. They are also called precipitation.
Evaporation is what happens when heat turns
water into water vapor. Water vapor is an
invisible gas found in the air. Depending on
conditions, it can either remain invisible or be
changed into visible water. Condensation is what
happens when water vapor turns back into a
liquid.
Most of the fresh water on Earth is frozen
as ice. When rivers and lakes overflow, or when
the ground can’t take in any more water, wetlands
form. You can also find groundwater, or fresh
water, trapped below Earth’s surface between
underground rocks.
The water cycle keeps water moving. Water
travels from Earth’s surface into the air and back
again. That’s how we get the steady supply of
fresh water we need to survive.

2

Water can be confusing to keep track of. After
all, it takes many forms and is constantly changing.
But without water, life could not exist. It is
important that we know what’s going on with
Earth’s water. This book will help you understand
how water gets around our planet.

3


The Water of Life
Rain is a type of precipitation. It falls from
the clouds to Earth’s surface in the form of
liquid droplets. Raindrops form when water
vapor condenses around small particles of dust.
When raindrops get too heavy for a cloud to
hold them, they fall to the ground. Then we
get wet!
Rain, if it falls too fast over too short a
period of time, can cause many problems for
humans and other living things. Heavy rain can
make it difficult or unsafe to
travel. It can even cause
natural disasters such
as mudslides and
flooding.Yet most of
the time, it is a lack of
rain that causes the most
harm to life on Earth.

4

Rain like this can cause heavy flooding, mudslides,
and other serious problems.

All living things need water to survive. Rain is
one way that many living things, such as plants

and trees, get the water they need to live.
Rainwater helps supply the water that our
bodies’ systems run on. We drink it, water our
crops with it, and cook with it. We also use it to
wash our clothes, manufacture goods, and make
electricity. For all of those reasons, the water that
comes from rainfall is critical to maintaining life.

5


Evaporation
Evaporation is an important
part of the water cycle. During
the process of evaporation, water
changes from a liquid state into
water evaporates
a gas.
Here’s how evaporation works.
The Sun heats up water in rivers, lakes, and oceans.
Once heated, the water turns into water vapor and
rises into the atmosphere. All exposed areas of
water, including swimming pools and reservoirs,
are heated by the Sun and evaporate.
On warm, sunny days large amounts of
water evaporate into the atmosphere.

6

Watery Planet

About 75 percent of
Earth’s surface is covered
with water. Look at this
view of Earth. Everything
that is blue or white is
some form of water!

Earth

Have you ever noticed steam rising from a cup
of hot cocoa or a bowl of chicken soup? If you
have, then you’ve seen evaporation with your own
eyes. Steam is what water can look like before it
turns to vapor and travels through the air.
A process called transpiration is another
way water moves back into the air. Transpiration
is what happens when plants release water into
the air through their leaves. It’s similar to the
process of perspiration, when water leaves the
human body as sweat and evaporates into the air.
Temperature plays a big role in evaporation.
The hotter the water, whether it is found in a
body of water or a living thing, the faster it
will evaporate.

7


Condensation
When water vapor cools in the

air, it turns into tiny water droplets.
The water has changed its form, or
state, from a gas back into a liquid.
This is a physical change called
clouds form
condensation.
A cloud is one visible result of condensation.
Clouds form when water vapor condenses and
turns to liquid high up in the atmosphere. When
you look at a cloud, what you are really seeing is
a large group of water droplets and ice crystals.

Now, think about the
last time you had a glass
of lemonade on a hot day.
You might have noticed
water droplets form on the
outside of your glass. If
you saw that happen, then
you witnessed another
example of condensation.
The water droplets that
form on cold glasses of
liquid come from the warm
air. They begin as water
vapor, which starts to cool
down when it first touches
the glass. Once it cools
down enough, it changes
state, or condenses, from

a gas to a liquid.

Cloud Types
The three main
types of clouds are
cirrus, cumulus, and
stratus. Have you
seen them before?

cirrus clouds

cumulus clouds

stratus clouds

8

9


Rain
Remember the water droplets
that form clouds? When enough
of them condense into large
enough particles, they fall as rain.
Clouds release the water droplets
Rain falls.
that they contain when the droplets
become too heavy for the clouds to carry.
Meteorologists usually classify water droplets

as rain when they reach a certain size. The diameter
of a typical raindrop measures between one-half
millimeter and four millimeters. Anything bigger
than four millimeters is likely to break up into
smaller drops.
Snow
In the United States,
rain and snowfall are
measured in inches. An
equal measure of snow
contains less water than
rain. It can take fourteen
inches of snow to equal
the amount of water in
one inch of rain!

10

Snow falling in the city

A rain shower contains raindrops of different
sizes. Individual raindrops change size and shape
as they fall. Such changes mostly happen when
individual raindrops bump into each other while
they are falling. Two raindrops might hit each
other and form a bigger droplet. Or they might
hit and break up into many smaller drops.
By using microscopes, scientists have been able
to describe the shape of water droplets. Most
raindrops start out in the shape of a sphere, but

end up being shaped like a hamburger bun!

11


Back to the Sea
Rain feeds Earth’s water systems.
Those systems include rivers, lakes,
streams, and oceans. Rivers, lakes,
and streams are all connected
through groundwater systems
Water returns
to the sea.
and the water cycle. Through
evaporation, precipitation, and the movement of
water, Earth’s water systems constantly interact.
When a raindrop gets too heavy for a cloud
to hold, it falls to Earth. That raindrop might fall
into a river. It might land on top of a tree, splatter
onto a flower, or drop to the ground. If you’re
outside, it might fall on you!
flowing river

12

Underground Water
Some water travels
deep underground.
When it reaches a layer
of rock that it can no

longer seep through, it
can form underground
lakes.
underground lake

Unless it lands in a body of water, a raindrop
is likely to either evaporate back into the air, or
be absorbed into the ground. Sometimes, the
ground reaches its saturation point and cannot
absorb any more water.
You can think of the ground as being like a
sponge. When a sponge has been filled with too
much water, the extra water spills out. When the
ground reaches its saturation point, the extra
water seeps out into streams, lakes, and wetlands.
From the streams, lakes, and wetlands, water
flows to rivers. Almost all rivers flow into the sea.
Water that flows into the sea can evaporate
immediately. It can also sink below the surface
and stay there for years.

13


The Complete
Water Cycle
A single raindrop is just a tiny part of the
water that moves through the water cycle.
Earth’s water is limited. But all of it moves
through the water cycle, which is always active.

The water cycle never stops changing water
from one form to another or moving it from
one place to another.
Heat from the Sun causes water to change
form as it travels. When not in its liquid form,
water travels as water vapor, or water that has
evaporated. Water also travels in clouds as water
droplets. It can also move from place to place as
precipitation when it rains, snows, or hails.

Everything on Earth is involved somehow
in the water cycle. Plants and trees give
off evaporated water that travels into the
atmosphere. When we sweat, the water
produced enters into the water cycle too.
Water reaches rivers, oceans, and lakes as
precipitation and run-off. Soil absorbs water,
which can trickle down to the rocks beneath the
soil. Plants and trees can absorb some of that
water to complete the cycle.
Much of the water cycle is visible. But other
parts are invisible. For example, in the summer,
single trees might evaporate hundreds of gallons
of water a day!
Clouds move
over land.

Water falls as
precipitation.
The Sun’s heat

warms water.

Water
evaporates.

14

Water vapor condenses
into tiny water droplets
and forms clouds.

Rivers and streams flow
back into the sea.
Water returns to the sea.

15


Vocabulary

Glossary
condensation
evaporation
atmosphere
groundwater
precipitation
water cycle
classify
water vapor
wetlands

natural disaster

Extended Vocabulary
atmosphere
classify
the molecule
whole mass of air
thatnatural
surrounds
Earth
disaster
perspiration
to assign
something to
saturation
a category
transpiration
a natural event that happens
suddenly and causes severe
damage

perspiration

the process of perspiring,
or sweating

saturation

being full of moisture

transpiration

the process of green plants
giving off water through
Picture Credits
their
leavescredit for photographic material.
Every effort has been made to secure permission and
provide appropriate
The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd).
Opener: Bruce Peebles/Corbis; 5 Bruce Peebles/Corbis; 6 (B) Color Box/ImageState; 10 (BR) Jose Luis Pelaez, Inc./Corbis;
11 Marc Muench/Getty Images; 12 (B) ©J. B. Pickering/Eye Ubiquitous; 13 Harolod Palo Jr./NHPA Limited.
Scott Foresman/Dorling Kindersley would also like to thank: 7 NASA/DK Images.
Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson.

ISBN: 0-328-13822-3
Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America.
This publication is protected by Copyright, and permission should be obtained from the publisher prior to any
prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,
mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to
Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.
3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05

16

What did you learn?
1. How are raindrops formed?
2. Why is rain important?
3. How big are raindrops?

4.

Every single
raindrop is part of the water cycle.
Write to explain how a raindrop
travels through the water cycle.
Include details from the book to
support your answer.

5.

Cause and Effect When water
vapor condenses and turns to liquid
high up in the atmosphere, what is
the effect?