1. Chemical Interactions
Unit 1
Chemical Interactions

2. Particles in Motion What is kinetic energy?
Moving objects, like particles, have energy
Movement energy is called kinetic energy
The amount of kinetic energy an object has depends on its mass and the speed it is moving

3. Changing Kinetic Energy
When particles speed up kinetic energy increases
Particles in substances move faster when they are heated
Heat increases kinetic energy

4. What happens when gases heat up?
Heated gas particles move faster and bump against each other so they have greater kinetic energy
Heated gas expands

5. What happens when liquids heat up?
Heated liquid particles move faster and have greater kinetic energy
Heated liquid expands

6. What happens when solids heat up?
Heated solid particles vibrate faster and have greater kinetic energy
Heated solid expands

7. What happens when particles cool?
When particles of matter are cooled they move slower and have less kinetic energy
Cooled matter contracts