Phase Changes
1. Phases of Matter / States of Matter:
 Solid
 Liquid
 Gas
2. Exothermic Phase Changes:
 Release energy to the surroundings
 Feel hot to the touch
 The kinetic energy of the substance decreases
 Phase changes that release energy:
- Depositing
- Condensing
- Freezing
3. Endothermic Phase Changes:
 Absorb energy from the surroundings
 Feel cold to the touch
 The kinetic energy of the substance increases
 Phase changes that absorb energy:
- Subliming
- Melting
- Vaporizing
 Evaporation happens at the surface only
 Boiling happens throughout the liquid
4. Heating Curve
 A graph that shows the change in temperature during phase changes
 During a phase change, the temperature remains constant because all of the
added/removed heat is weakening/strengthening the IMF’s and the kinetic
energy of particles does not increase until this process is finished
Boiling Point
Melting Point