1. Physical & Chemical Changes

2. Physical vs. Chemical Change
Physical Change -
Change that affects only the physical properties of a substance
Physical properties include:
Size, Shape and Phase of matter
Appearance changes – not chemical makeup

3. Physical vs. Chemical Change
Results from chemical reactions in which one or more new substances are formed
End products are chemically different from the original.
Corrosion-dissolving away metal-rusting.

4. Physical vs. Chemical Change
Identify the following as physical or chemical change.
Ice cube melting.
People eating.
Wood burning.
Slicing an apple into pieces.

5. Changes in Matter - Continued
Melting Point –
Temperature at which a solid changes
to a liquid
Example: Ice  water
Freezing Point –
Temperature at which a liquid changes
to a solid
Example: Water  Ice (0°C)

6. Changes in Matter Boiling Point –
Temperature at which a liquid changes
into a gas
Example: Water  vapor (100˚ C)

7. Changes in Matter - Continued
Evaporation-
process at which a liquid changes to a gas at boiling point
Example: water boils to form steam

8. Changes in Matter - Continued
Condensation –
Process at which a gas becomes a liquid
Gas cooled below its boiling point
Example: water vapor  water, dew in the morning, glass of ice tea in hot weather.

9. Changes in Matter - Continued
Sublimation –
When a solid changes directly to a gas
The matter doesn’t melt
Example:snow, dry ice and glaciers
Deposition-
Gas changes directly into a solid

10. Changes in Matter - Continued
Exotic Super Hot
Nucleus of atom comes apart
Particle accelerates
Exotic Super Cold
Below -270˚ C
Superfluids from gases