Changes in matter

chemical change mixture physical change solution states of matter What did you learn?. A physical change is when matter changes the way it looks but does not become a new kind of matter

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by Lorrie Oestreicher

Scott Foresman Science 3.11

Genre Comprehension Skill Text Features Science Content

Nonfi ction Cause and Effect • Captions

• Glossary

Changes in Matter

ISBN 0-328-13838-X

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Physical Science

Scott Foresman Science 3.11

Genre Comprehension Skill Text Features Science Content

Nonfi ction Cause and Effect • Captions

• Glossary

Changes in Matter

ISBN 0-328-13838-X

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Physical Science

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chemical change

mixture

physical change

solution

states of matter

What did you learn?

1 What are three states of matter?

2 Why is cutting paper a physical change?

3 Is a salad a mixture? Why or why not?

read about dissolving salt in water Write to explain why it is a mixture and how you could demonstrate this Use details from the book

as you write

5 Cause and Effect What causes water

to turn into ice? What is the effect on the state

of matter?

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ISBN: 0-328-13838-X

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Changes in Matter

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What are physical changes

in matter?

Making a Physical Change

Workers are carving this mountain into a statue of

the Native American leader Crazy Horse They must

blast away and hammer bits of rock to do this

The workers are causing a physical change to

the mountain A physical change is when matter

changes the way it looks but does not become a new

kind of matter This mountain looks different Its

shape has changed But it is still a solid mountain

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Some Ways to Cause Physical Change

The clothes and paper in these pictures have gone

through physical changes The clothes were folded

The paper was cut

One kind of physical change is when matter

changes form, or state States of matter are the

different forms matter can have They are solid, liquid,

and gas The state of matter can change But the kind

of matter stays the same

Folding clothes causes a physical change. Cutting paper causes

a physical change.

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Water can change its state of matter Freeze a cup

of water It turns into ice It changed from a liquid to

a solid The state changed, but the kind of matter did not Water and ice are the same kind of matter If you melt the ice, it is still water Its state changed from a solid back to a liquid

This water is

a solid.

This water is

a liquid.

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Changes in temperature can cause matter to

change its state If you boil water, its state changes

It evaporates That means it changes into a gas called

water vapor A physical change takes place The gas

is still a form of water But you cannot see it The

water particles are far apart in the air The water

has changed state But it has not become a new

kind of matter

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Ice is water in a solid state It can change to a liquid Hold an ice cube in your fist The particles in

a solid vibrate in place The heat from your hand changes it The heat makes the particles slide past one another You feel water drip from your hand A physical change takes place But the kind of matter is still the same

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What are some ways

to combine matter?

Mixtures

Each coin you see below is made up of matter

Putting different coins together makes up a mixture

A mixture is made of two or more kinds of matter

that are placed together There can be different

amounts of each kind of matter in a mixture

In mixtures, the matter does not change into new

matter You can separate each kind of matter from

the others

A magnet can help separate this mixture of sand and iron.

How many of each

type of coin make

up this mixture?

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Some mixtures are very easy to separate The coins are easy to separate A strainer can help separate some mixtures The bigger matter stays in the strainer The smaller matter passes through the holes A sand and iron mixture is harder to separate A magnet can pull the iron out The sand is left behind

A strainer helps separate the parts of this marble and sand mixture.

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Solutions

Mix lemonade powder and water together The

lemonade powder will look as if it has disappeared

But it is still there Its particles have just become

too small for you to see The powder has dissolved,

or broken down, in the water It is now a solution

A solution forms when one or more substances

dissolve in another It is a kind of mixture You

cannot see the powder But you know it is there

when you taste the lemonade

There are many kinds of solutions Soda is a

solution Carbon dioxide gas and other substances

are dissolved in water to make soda

The carbon dioxide gas dissolved in this soda is escaping.

This glass of lemonade

is a solution.

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Solutions can be separated since they are mixtures

Salt dissolves in water You can separate this mixture if you boil the salt water The water evaporates The salt

is left

Both the lemonade and the salt dissolved in water

But even these changes are just physical changes The kind of matter in each solution is still the same

Straining doesn’t separate the salt from salt water.

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What are chemical

changes in matter?

Forming Different Materials

Have you ever watched bread being made? It starts

as a mixture Flour, water, baking powder, and other

ingredients are mixed in a bowl After it is baked, you

have bread Baking the bread in an oven causes a

chemical change During a chemical change, one

kind of matter changes into a different kind of matter

The heat of the oven causes a new substance to form

Bread is the result

Baking bread causes a

chemical change.

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Chemical changes can happen quickly or slowly

Fire changes paper or wood into ashes It takes only minutes Rust forms on an iron chain very slowly over time The iron changes into rust A new kind of matter forms

You cannot often get the original matter back after

it has gone through a chemical change You cannot easily change the rust back into iron You cannot change the ashes back into paper You cannot change bread back into its ingredients

Rusting is a slow chemical change.

Burning is a fast chemical change.

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Using Chemical Changes

We use chemical changes every day When we eat

food, chemical changes take place As the food moves

through your body, it changes It gives your body

energy It helps you grow

Cars burn gasoline when they run The chemical

change sends energy through the car engine

Chemical changes help make things easier to do

Soap causes chemical changes that remove stains

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Another chemical change lets you use your CD player You push the buttons to play it Chemicals combine inside the batteries New substances form

A small amount of electricity is produced Now you can hear your favorite music

Matter can change in many ways It can change states It can be combined in different ways These changes make many things possible

Chemical changes turn milk into cheese.

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Glossary

chemical change a change of one kind of matter

into a different kind of matter

mixture two or more kinds of matter

placed together

physical change a change in which matter looks

different but does not become a new kind of matter

solution when one or more substances

dissolve in another

states of matter the forms that matter can take:

solid, liquid, or gas

Vocabulary