States of Matter A. The Kinetic Theory 1. All matter is composed of small particles (atoms, molecules, or ions). 2. They are in constant, random motion. 3. They constantly collide with each other and with the walls of their container.

B. Phase Properties Particle Properties Phase Proximity Energy Motion Volume Shape Solid close little vibrational definite definite Liquid close moderate rotational definite indefinite Gas far apart a lot translational indefinite indefinite

C. Other States 1. Solids with particles in repeating geometric patterns are crystals. Those with particles arranged randomly are amorphous. 2. Plasma a. Hot, ionized gas particles. b. Electrically charged. c. Most common state in universe.

D. Thermal E x p a n s i o n 1. Particles in any state expand when heated (generally). 2. Examples of solids: a. Expansion joints b. Power lines c. Thermostats 3. Different materials expand at different rates.

4. Mercury and alcohol are liquids that expand in thermometers 5. Air expands when heated (becoming less dense) 6. Water reaches maximum density at about 4 C. Ice particles are farther apart than liquid water (so it floats).