1. Chemical Reactions

2. Elements, Mixtures and Compounds

4. Identifying Changes
Physical Changes
Physical state
Chemical Changes

5. Types of Change Type of Change Products of Change Physical Change
No new substance, but physical state is changed.
Example:_____________________
Chemical Change
New substances are formed.
Also called a chemical reaction.

6. Chemical Reactions Color Change Temperature change Change in odor
A chemical reaction is a process in which atoms of one or more substances rearrange to form one or more new substances.
When a new substance(s) is formed, there are indications.
Color Change
Change in odor
Formation of Bubbles
Formation of Precipitate
Temperature change
Light

7. Chemical Reactions and Chemical Equations
Chemical reactions are written in the form of a chemical equation.
The starting substances are called the reactants.
The substances produced, or formed, are called the products.
Reactant + Reactant  Product + Product
Eg.

8. Types of Chemical Reactions
There are four major types of chemical reactions.
1. Synthesis: two or more combine and form one compound eg.

9. 2. Decomposition: one compound breaks down into two or more.
eg.

10. 3. Replacement: an atom (or a group) in a compound is replaced by another atom (or a group)
Single replacement: element replaces another element in a compound.
Double replacement:  positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products.

12. 4. Combustion: a substance reacts with oxygen and releases energy.
Eg.