1. States of Matter Phase Change

2. Water Water exists on our planet in three states. Ice, water, and water vapor What causes water to be in one phase or another?

4. ENERGY When energy is added to a substance that energy causes the particles in the substance to move faster and farther apart.

5. Phase Change Energy content is responsible for the different phases of matter. Matter can be made to change phase when energy is added to or taken away from a substance.

6. Melting- Solid to Liquid Melting is the changing of a solid to a liquid The solid heats up and absorbs heat energy. If the particles vibrate fast enough, the particles break loose and slide past on another Happens at the melting point

7. Freezing- Liquid to Solid Opposite of melting: liquid changing to a solid is freezing. Freezing occurs when a substance loses heat energy and the particles sow down. Eventually they attract to one another and become solid. Happens at the freezing point.

8. Evaporation- Liquid to Gas Evaporation is the changing of a liquid to a gas. The liquid particles gain energy and eventually break away from liquid and escape as gas particles. Happens when temperature increases.

9. Boiling Process of a liquid becoming a gas. Heat a liquid, large bubbles rise and go to the surface. Happens at the boiling point.

10. Condensation- Gas to Liquid Gas to liquid phase change. A substance in the gas phase that loses energy and particles slow down will change to a liquid. Happens over a large range or temperatures.

11. Condensation Water vapor in surrounding air loses heat energy when it comes in contact with the cold glass. Water vapor condenses and becomes liquid drops of water.

12. Sublimation – Solid to Gas Solid to gas phase change occurs when the surface particles of a solid change directly into a gas.

13. Sublimation – Solid to Gas You may notice this in the cold winter with snow. The snow does not melt, but slowly disappears. Dry ice goes directly from solid carbon dioxide to gas.