1. Chapter 20
How Chemicals React

2. Chemical Reactions are Represented by Chemical Equations
Reactants  Products Law of mass conservation- matter is neither created nor destroyed.

3. Balancing Chemical equations

4. Chemical Reactions Can Be Slow or Fast
The reaction rate is how fast a reaction takes.

5. Activation Energy
Activation energy- the minimum energy required to start a reaction.

6. Catalysts
A catalyst is a substance that speeds up a reaction.

7. Exothermic and Endothermic Reactions
Exothermic reactions – Release energy ( fire explosions)
Endothermic reactions- absorb energy ( cold compress)