Particles get more kinetic energy and begin rotating around each other.

1. Melting - solid to liquid • Particles get more kinetic energy and begin rotating around each other. • There isn’t enough energy to break the intermolecular attractions, so the particles remain close (liquid). • The energy required to melt a solid is called the heat of fusion.

2. Freezing - liquid to solid • Particles lose kinetic energy and slow down. • Attractive forces between particles become stronger than the particles’ motion, so the particle sget closer together and begin merely vibrating in place. • The amount of heat the particles must lose to turn into a solid is called the heat of fusion.

3. Types: • Boiling - rapid; gas bubbles are produced throughout. • Evaporation - slow; occurs at the surface. • Liquid particles gain enough kinetic energy to overcome forces between the particles and they begin translational motion; this energy is called the heat of vaporization. Vaporization - liquid to gas

4. Evaporation is a cooling process. • Particles in a liquid gain kinetic energy. • They leave as gas particles (taking the energy away with them). • This leaves less energy in the liquid, therefore cooling down what is left.

5. Condensation -gas to liquid • Particles lose kinetic energy, slow down, and come closer together. • Intermolecular forces become strong enough to make particles merely rotate around each other. • The energy they lose to turn into a liquid is the heat of vaporization.

6. Sublimation - solid to gas • A solid changes directly to a gas without going through the liquid phase. • Dry ice - carbon dioxide • Iodine • Frost