1. Solid phase (s): Strong attractive forces hold particles in fixed location. Regular definite geometric shape; crystalline Liquid phase (l): Particles have mobility; sufficient attractive forces to give liquids a definite volume. Gaseous phase (g): Particles have minimal attractive forces holding them together. No definite volume or shape. States of Matter

2. Vocabulary Temperature: A measure of the average kinetic energy of its particles. (°C or K) Heat: a measure of the amount of energy transferred from one substance to another. (J) Heat of fusion: The amount of heat needed to convert a unit mass of a substance from solid to liquid at its melting point. (H f ) Heat of vaporization: The amount of heat needed to convert a unit mass of a substance from its liquid phase to its vapor phase at constant temperature. (H v )

3. Phase Changes Fusion: Melting; when particles have enough potential energy to break foa’s holding them together. Freezing: liquid to solid (solidification) Vaporization: Boiling; When particles have enough kinetic energy to enter the gas phase. Condensation: gas to liquid Sublimation: solid to gas Deposition: gas to solid