States of Matter Solid phase s Strong attractive

States of Matter 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.

Aim: How can one interpret the heating curve for a substance? • The structure and arrangement of particles and their interactions determine the physical state of a substance at a given temperature and pressure. • The three phases of matter (solids, liquids, and gases) have different properties.

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. (Hf) • 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. (Hv)

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