Temperature, Heat, and Thermal Energy Kinetic theory—explains how particles in matter behave All matter is composed of small particles. Particles are in constant, random motion. Particles collide with each other and walls of their containers.

Thermal energy—total energy of a material’s particles; causes particles to vibrate in place Temperature is the average kinetic energy of a substance, or how fast the particles are moving. The lower the temperature, the slower the particle motion

from Celsiusto Celsius Fahrenheit[°F] = [°C] × 9 ⁄ [°C] = ([°F] − 32) × 5 ⁄ 9 Kelvin[K] = [°C] [°C] = [K] − Temperature Conversions

States of Matter and Phase Changes

Thermal expansion—increase in the size of a substance when the temperature increases The size of a substance will then decrease when the temperature decreases. Expansion and contraction occur in most solids, liquids, and gases. Water is an exception because it expands as it becomes a solid.

Boyle’s Law—relates pressure and volume Volume decreases as pressure increases. Pressure decreases as volume increases. Pressure multiplied by volume is always equal to a constant if the temperature is constant. P1V1 = P2V2

Charles’s Law—relates volume and temperature At a constant pressure, volume increases as temperature increases. At a constant pressure volume decreases as temperature decreases. V1T1 = V2T1 Temperature must be in Kelvin

Gay-Lussac’s Law—relates pressure and temperature; at a constant volume As temperature increases, pressure increases As temperature decreases, pressure decreases P1T2 = P2T1