1. Chapter 8
Phase Changes

2. Intermolecular Forces
When molecules are close together, they are attracted through intermolecular forces.
The forces in chemical bonds are stronger than intermolecular forces.

3. Phase Changes Process Starting Phase Ending Phase Melting Boiling
Condensing
Sublimation
Freezing
Deposition
solid
liquid
liquid
gas
gas
liquid
solid
gas
liquid
solid
gas
solid

4. Plasma
In the plasma phase, matter becomes ionized as electrons are broken loose from atoms.
The Sun is made of plasma, as is most of the universe, including the Orion nebula.

5. Heating and Cooling Curves
Temperature ( oC )
Time (s)