dissolve evaporate freeze melt Picture Credits Every effort has been made to secure permission and provide appropriate credit for photographic material.. Melt means to change to a liqui
Trang 1ISBN 0-328-23470-2
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Standard Set 1 Physical Sciences
1 Materials come in different forms
(states), including solids, liquids, and
gases As a basis for understanding
this concept:
1.b. Students know the properties
of substances can change when the
substances are mixed, cooled, or
heated.
Genre Comprehension Skill Text Feature Science Content
Nonfi ction Put Things in Order • Glossary Matter
Scott Foresman Science 1.2
Standards Preview
by Nancy Day
Physical Sciences
Trang 2dissolve
evaporate
freeze
melt
Picture Credits
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publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions
Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd)
11 ©Royalty-Free/Corbis; 14 Dave King/DK Images, (BL) Martin Cameron/DK Images
ISBN: 0-328-23470-2
Copyright © Pearson Education, Inc All Rights Reserved Printed in the United States of America
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1 2 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06
by Nancy Day
Trang 3How can things
change?
Things can change.
Mixing changes some things.
2
Heating changes some things.
Cooling changes some things.
3
Trang 4Making Crayons
Wax is a solid.
Wax is used in crayons.
Heating can change wax.
Heating melts the solid wax.
Melt means to change to
a liquid
Melted wax
is poured into
each hole.
4
Color is mixed in the liquid wax.
The wax is cooled.
The wax becomes solid.
5
Wax is shaped into crayons.
Trang 5What properties
of things can
change?
Size, shape, and color are
properties
A candle can change.
Heating melts the candle.
Heating changes its shape.
6
How something feels is a property.
Clay feels soft.
Heating changes how clay feels.
Heating makes clay feel hard.
7
Trang 6What changes
when things are
mixed?
Water is a liquid.
Chicken and noodles are solids.
Solids mix with liquid in soup.
But you can take solids out.
8
Salt is a solid.
Some solids dissolve in liquids.
Dissolve means to spread
throughout a liquid.
Salt dissolves as it is mixed in water.
You cannot see salt after it dissolves.
9
Trang 7How can cooling
and heating
change things?
Water is a liquid.
Water freezes if it is
very cold.
Freeze means to change
from a liquid to a solid.
Ice is solid.
Ice is frozen water.
10
Heating melts ice.
Ice changes to water.
Water can freeze.
It can change back into ice
11
Trang 8Changing Water into a Gas
When water is heated, it
evaporates.
Evaporate means to change
from a liquid to a gas.
The water goes into the air.
12
Mix salt in water
The salt dissolves
The water evaporates
The salt stays
13
Trang 9What things
cannot change
back?
Some things that are heated
cannot change back.
Heating changes an egg.
It cannot change back.
14
Heating changes corn into popcorn.
It cannot change back.
15
Trang 10dissolve spread throughout a liquid
evaporate change from a liquid to a gas
Glossary
16
1 What does salt do in water?
2 When water is heated, what happens?
watched eggs being cooked for breakfast? Describe what happened Use all fi ve
senses in your description.
4 Put Things in Order Tell what happens
to water after it rains Use the words fi rst, next, and last.
What did you learn?