1. Notes 2-2
Changes in Matter

2. Physical Changes
Alters form or appearance of matter but does NOT change matter into a different substance
Examples:
-Changes of state (solid to liquid, or liquid to gas, etc.)
-Changes in shape or form (dissolving, chopping, cutting, bending, breaking, etc)

3. Chemical Changes
A change in matter that produces one or more new substances
Chemical change = chemical reaction
New substances have properties different from original substances
Examples:
-burning of natural gas on gas stove (combustion)
-rusting (oxidation)

4. Chemical Change

5. Law of Conservation of Matter
Matter is neither created nor destroyed in any physical or chemical change
No mass is lost, because during a chemical change, atoms are not lost or gained, just rearranged.

6. Conserving Matter
The idea of atoms explains the law of conservation of matter. For every molecule of methane that burns, two molecules of oxygen are used. The atoms are rearranged in the reaction, but they do not disappear.