1. Changes in Matter

2. All matter can change in form!
In other words, matter can change from one state to another.
Solids can become liquids and gases.
Liquids can become solids and gases.
Gases can become solids and liquids.

3. What causes matter to change form?
Heat
The addition of heat causes molecules to move faster and farther apart.
The removal of heat causes molecules to move slower and closer together.

5. When a solid is heated… Molecules expand and vibrate faster
This causes the solid to become a liquid
This process is called MELTING

6. Melting Point
The temperature when a substance turns from a solid to a liquid.

8. Melting Point All matter has a melting point
The melting point is also the freezing point
The most common melting point is of water (ice)
The melting point of water is 0 degrees Celcius or 32 degrees Fahrenheit

9. When a liquid is heated…
Loose molecules continue to expand and movement increases
This causes the liquid to become a gas
This process is called BOILING

10. Boiling Point
The temperature when a liquid turns into a gas.

11. Boiling Point All matter has a boiling point
The most common boiling point is of water
The boiling point of water is 100 degrees Celcius or 212 degrees Fahrenheit
This process is also called EVAPORATION

13. When heat is removed…
Removing heat causes the reverse changes in matter
When a gas is cooled it will turn into a liquid (this is called CONDENSATION)
When a liquid is cooled it will turn into a solid (think of putting water (liquid) in the freezer-you get ice (solid)

14. Condensation

15. Questions

16. What causes a solid to become a liquid?

17. Adding heat
Melting Point

18. What causes a gas to become a liquid?

19. Condensation
Taking heat away