1. Physical Phase Changes

2. Physical Changes in Matter
Matter can change physically
It however will remain the same substance, but in a different form.
Examples: melting, freezing, boiling

3. Phase Change Diagram

4. Phase Change Diagram
Plateau - Temperature does not increase

5. absorbs heat energy as atoms speed up
Melting Point
solid turns to liquid
absorbs heat energy as atoms speed up
ex. Ice melts at 0°Celsius

6. Freezing point liquid turns to solid
releases heat energy as atoms slow down
ex. Water freezes at 0°Celsius

7. Decrease in Temperature

8. Vaporization Boiling Change of state from liquid to a gas
occurs at a liquid’s
boiling point and
occurs throughout
the liquid.
Ex. Water boils at ° C

9. Evaporation Vaporization water evaporates slowly from the
surface of the
liquid.
Ex. Water absorbs energy from your skin, you feel cooler

10. Temperature Increases

11. Sublimation
Process of changing a solid to a gas directly without the liquid stage.
Absorbs heat as atoms increase speed.
Ex: Dry ice (frozen CO2) sublimes

12. Condensation
Process of changing a gas to a liquid. Releases heat as atoms slow down.
Example: water condenses on mirror when taking a hot shower.

13. Phase Diagram D E C B A

14. Exothermic reaction- chemical reaction in which energy is released or removed. Cold reaction
Endothermic reaction- chemical reaction in which energy is absorbed. Hot Rx.