2. Main Points All matter is made up of invisible particles Particles have spaces between them Particles are moving all the time Particles move faster when they are heated Particles attract each other

3. The Particle Theory & Heat Object heated – particles move faster Object cooled- particles move slower

4. Particle Theory & Heat [Cont’d] Warm object touches cold object Fast- moving particles in warm bump into slow- moving particles in cold Particles in cold speed up; particles in warm slow down

5. Heat The transfer of energy from the particles of warmer objects to the particles of cooler objects

6. Kinetic Energy Energy all moving objects possess Particle has more kinetic energy when moving faster Particle has less kinetic energy when moving slower

7. Kinetic Energy [Cont’d] Kinetic energy keeps particles moving all the time (never stand still) Not all particles move at same speed:  Collide randomly- some speed up; some slow down Particles do not all possess same amount of kinetic energy

8. Temperature Most particles in hot object move faster than most particles in cold object  Hot = higher average kinetic energy than cold Temperature: A measure of average kinetic energy of particles in a substance

9. Heat Transfer Heat is transferred (moved) by 3 methods: Conduction Convection Radiation