Physical Changes

• Changes in matter that do not alter the identity of the matter itself.
• For example:
  1. Size
  2. Shape
  3. State - solid liquid  gas
  4. Dilutions

Chemical Changes

• Changes that do alter the identity of a substance.
• For example:
  1. Iron rusting

     4 Fe(s) + 3 O_2(g) 2 Fe₂O₃ • 3 H₂O

  2. Wood burning
  3. Copper turning to brass

Common Errors

• Ice melting, water freezing, water evaporating, and steam condensing are all examples of a state change.
  • These are physical changes, not chemical.
• Diluting a solution is a physical change, even if the color becomes more faint.

Next:  "Significant Figures"