1. Physical vs. Chemical Change

2. Physical Change:
Alters the appearance of the substance without changing its composition.
No new substance is formed.
Tearing, Grinding
Phase Changes
Dissolving

3. Chemical Change:
A chemical reaction has occurred and a new substance is formed.
Reactants  Products
Burning or Combustion
Alcohol + Air  CO2 + H2O + Heat
Oxidation or Rust
Iron + Air  Rust

4. Indication of a Chemical Change
Color change
Temperature change
Bubbles
Precipitate (a lot of little particles form)

6. Video Link
Physical and Chemical Change

7. Physical or Chemical Change?
Breaking a Pencil
Physical change
Wood Burning
Chemical change
Silver Tarnishing
Ice Melting
Hard Boiling an Egg

8. Conservation of Mass Also known as “law of conservation of matter”.
Mass is neither created nor destroyed in a chemical reaction.
Mass of the reactants equals the mass of the products.
2g Hydrogen + 16g Oxygen  ?g Water
18g

9. Video Link
Conservation of Mass