1. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

2. Unit 9 Lesson 2 What Are the States of Matter?
What’s the State?
There are three common states of matter: solid, liquid, and gas.
Copyright © Houghton Mifflin Harcourt Publishing Company

3. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

4. Space ( Volume ) Shape Solids Liquids Gas Definite amount Definite
Unit 9 Lesson 2 What Are the States of Matter?
Space
( Volume )
Shape
Solids
Liquids
Gas
Definite amount
Definite
Definite amount
Not
definite
Not a definite amount
Not
definite
Copyright © Houghton Mifflin Harcourt Publishing Company

5. Unit 9 Lesson 2 What Are the States of Matter?
What’s the State?
A solid is matter that takes up a definite amount of space. Solids also have a definite shape.
Your science book is a solid. Ice is also a solid.
Copyright © Houghton Mifflin Harcourt Publishing Company

6. Unit 9 Lesson 2 What Are the States of Matter?
What’s the State?
A liquid is matter that takes up a definite amount of space but does not have a definite shape.
Liquids take the shape of their containers.
Drinking water is a liquid.
Copyright © Houghton Mifflin Harcourt Publishing Company

7. Unit 9 Lesson 2 What Are the States of Matter?
What’s the State?
A gas is matter that does not take up a definite amount of space and does not have a definite shape.
The air around you is a gas.
Copyright © Houghton Mifflin Harcourt Publishing Company

8. Cool! It’s Freezing! When water is cooled enough, it freezes.
Unit 9 Lesson 2 What Are the States of Matter?
Cool! It’s Freezing!
When water is cooled enough, it freezes.
Freezing is the change of state from liquid to solid.
Copyright © Houghton Mifflin Harcourt Publishing Company

9. Solid Liquid Gas Melting Evaporation Freezing Condensation
Unit 9 Lesson 2 What Are the States of Matter?
Solid
Liquid
Gas
Melting
Evaporation
Freezing
Condensation
Copyright © Houghton Mifflin Harcourt Publishing Company

10. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

11. Cool! It’s Freezing! Below the freezing temperature, water is a solid.
Unit 9 Lesson 2 What Are the States of Matter?
Cool! It’s Freezing!
Below the freezing temperature, water is a solid.
Hail, ice on a lake, and a snowball are examples of solids. Each of these examples is water frozen into a solid.
Copyright © Houghton Mifflin Harcourt Publishing Company

12. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

13. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

14. Unit 9 Lesson 2 What Are the States of Matter?
Just Add Heat!
When water is heated, it gains energy. If ice is heated enough, it melts.
Melting is the change of state from a solid to a liquid. Melting is the opposite of freezing.
Water melts above 0 °C (32 °F) and freezes below 0 °C (32 °F).
Copyright © Houghton Mifflin Harcourt Publishing Company

15. Unit 9 Lesson 2 What Are the States of Matter?
Just Add Heat!
If enough energy is added to water, it boils and changes to a gas.
Water boils at 100 °C (212 °F).
Water in the form of gas in called water vapor. Water vapor is invisible.
Copyright © Houghton Mifflin Harcourt Publishing Company

16. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

17. Unit 9 Lesson 2 What Are the States of Matter?
Now You See It …
Liquid water can change to a gas without boiling. This process is called evaporation.
Water evaporates from puddles on a warm day.
Copyright © Houghton Mifflin Harcourt Publishing Company

18. Now You See It … What happened to the water?
Unit 9 Lesson 2 What Are the States of Matter?
Now You See It …
What happened to the water?
Copyright © Houghton Mifflin Harcourt Publishing Company

19. Unit 9 Lesson 2 What Are the States of Matter?
Now You See It …
A gas can change back to a liquid in a process called condensation.
When water vapor loses energy, such as on a cold window pane, it changes to a liquid.
Copyright © Houghton Mifflin Harcourt Publishing Company

20. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

21. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company

22. Unit 9 Lesson 2 What Are the States of Matter?
Copyright © Houghton Mifflin Harcourt Publishing Company