1. Chemical Reactions

2. Reactions
The change one or more substances into other substances is a chemical reaction
2H2 + O2  2 H2O
A chemical equation needs to be balanced
This means you need the same number of atoms on each side of the equation

3. Mixtures and Solutions
A mixture is a combination of 2 or more components that retain their identity
A heterogeneous mixture is one that the components are recognizable
Soil is an example
A homogeneous mixture is one that parts cannot be distinguished, even though they also retain their properties
Coffee or Kool Aid is an example
Homogeneous mixtures are also called solutions

4. Acids and Bases
An acid is a solution containing a substance that produces hydrogen ions (H+) in water
H2O + CO2  H2CO3
Bases produce hydroxide ions (OH-) in water
The pH scale measures the hydrogen and hydroxide ions in solutions
0-6 represents an acid, 7 is neutral, and 8-14 is a base