1. Chemical Reactions
Chapter 2.4

2. Chemical Changes
Burn, rot, rust, decompose, ferment, explode, and corrode
During a chemical change, the composition of matter always changes.

3. Chemical Reaction
When one or more substances change into one or more NEW substances
Reactant at beginning  product at end

4. Was That A Chemical Change?
Transfer of energy
Change in color
Production of a gas
Formation of a precipitate (solid)

5. Conservation of Mass
During chemical rxn. mass of product always = mass of reactants
(Law of Conservation of Mass: mass is neither created nor destroyed)