Kinetic Theory
1. Kinetic Theory Explains how particles move in matter Three basic assumption (a) all matter is composed of small particles (b) these particles are in constant, random motion ‘© particles collide with each other and the walls of their container
2. Thermal Energy Total energy of a material’s particles (includes both kinetic and potential energy)
3. Average Kinetic Energy Fancy word for “temperature” Identifies how fast (or slow) the particles are moving Zero degrees moves slower than 50 degrees At absolute zero (-273.15 Celsius)…close to no movement of particles at all
4. Solid State Particles are closely packed together Rely on a specific type of geometric arrangement
5. Liquid State Melting Point – temperature at which a solid begins to liquefy Heat of Fusion – amount of energy required to change a substance from a solid to a liquid Has to do with kinetic energy…more in a liquid than a solid
6. Gas State (Vaporization) Particles in a gas state have enough kinetic energy to overcome any attraction to each other Two types of vaporization: evaporation and boiling
7. Evaporation Vaporization that occurs at the surface of a liquid Can occur at temperatures below the liquids boiling point
8. Boiling (Type of Vaporization) Boiling Point – temperature at which the pressure of the vapor in the liquid is equal to the external pressure acting on the surface of the liquid (push down) Heat of vaporization – amount of energy required for the liquid at its boiling point to become a gas
9. Recap Solid – definite volume, definite shape, arranged in geometric patterns, Liquid – definite volume, no definite shape Gas – no definite volume, no definite shape, move in all directions until spread evenly (diffusion)
10. Plasma Most common state of matter in universe Contains positively and negatively charged particles that create a neutral charge Gas-like; no definite volume, no definite shape
11. Thermal Expansion Increase in the size of a substance when the temperature is increased (Converse is also true – decrease with decrease in temperature) Examples: thermometer, hot air balloon, creases in sidewalks EXCEPTION is water – ex: ice