1. Chemical Kinetics – collision theory
Relate rates of chemical reactions to collisions between reacting particles.

2. Main Idea
Collision theory is the key to understanding why some reactions are faster than others.

3. The reaction rate of a chemical reaction is stated as the change in concentration of a reactant or product per unit of time.

4. Reaction rates are determined experimentally.

5. Collision theory states that atoms, ions, and molecules must collide in order to react.

6. An activated complex is a temporary, unstable arrangement of atoms in which old bonds are breaking and new bonds are forming.

7. The minimum amount of energy that reacting particles must have to form the activated complex and lead to a reaction is called the activation energy.
High activation energy means that few collisions have the required energy and the reaction rate is slow.