SolidsSolid- has a definite volume and a definite shape.

Motion of particles are restricted in solids because of the stronger intermolecular forces.

Defn. Crystalline Solid: consists of crystals which the particles are arranged in an orderly geometric repeating pattern.Defn. Amorphous Solid: A non-crystalline solid in which the particles are arranged randomly. Characteristics of Solids1. Definite Melting Point: temperature in which a solid becomes a liquid.2. High Density and Incompressibility:

3. Low Rate of Diffusion

Defn: Crystalline Structure: total three dimensional arrangement of particles of a crystal.Defn: Unit Cell: The smallest portion of a crystal lattice that shows the three dimensional pattern of the entire lattice.

Changes of StateDefn: Phase: any part of a system that has uniform composition.

Defn: Equilibrium: A dynamic condition in which two opposing changes occur at equal rates in a closed system.Defn: Equilibrium vapor pressure: Pressure exerted by a vapor in an equilibrium with its corresponding liquid at a given temperature.

Defn: Volatile liquid: Liquids that evaporate readily.

Defn: Molar enthalpy of vaporization:∆Hv Amount of energy needed to vaporize one mole of liquid at the liquids boiling point. Temperature at the boiling point remains constant despite the amount of energy added.

Defn: Molar enthalpy of fusion ∆Hf Amount of energy needed to melt one mole of a solid.

Defn: Phase Diagram: A graph of pressure versus temperature that shows the condition under which the phases of a substance exists.

Defn: Critical Temperature: the temperature above which the substance cannot exist in the liquid state.

Defn: Triple point: Indicates the temperature and pressure conditions at which the solid, liquid and vapor of the substance can co-exist at equilibrium.