2. What is a chemical
reaction?
A reaction in which something
new is created
What are some common
chemical reactions?

3. Evidence of a Chemical
Reaction:
1- gas production
2- odor
3- color change
4-precipitate (solid) is formed
5- energy change (heats up/cools
down)

4. Chemical Equations
Parts:
1- Reactants: chemicals we start with (left of arrow)
2-Products: new chemicals produced from the rxn (right of
the arrow)
3-Arrow: means a rxn is taking place
4- Plus sign: separates different chemicals in a rxn
H2 + O2  H2O