1. Signs of Chemical Change

2. 1. Gas and Bubbles
Gas released
Not boiling

3. 2. Color Change
Color changes from one to another

4. 3.Temperature Change Exothermic: heat is released.
Temperature rises – hot.
Exo- Out
Example: combustion.

5. 3.Temperature Change Endothermic: heat is absorbed.
Temperature drops -cools
Endo -In
Example:

6. 4. Precipitate
Two liquids come together to form a semi-solid substance.

7. 5. New Product New arrangement of the atoms.
A new products is present that was not there before.
New properties

8. Law of Conservation of Mass
In 1789 Antoine Lavoisier discover that mass is neither created nor destroyed in chemical reactions.
In a chemical reaction the total mass of the reactants is always equal to the total mass of the products.