1. Physical & Chemical Changes

2. Types of Changes:
Two Types of Changes
Physical Change
Chemical Change

3. Physical Change:
Does not change the chemical composition or the nature of a substance
Process is easily reversible
Ex. Crumpling & smoothing out paper
Ex. Freezing water and thawing ice
Ex. Sublimation – from solid to gas (ex. dry ice (CO2) or iodine)

4. Key Words: Crush/Pulverize Melt Evaporation Condensation Sublimation
Tells you a
physical change
occurred
Key Words:
Crush/Pulverize
Melt
Evaporation
Condensation
Sublimation
Solidification
Dissolve

5. Chemical Changes:
Changes the chemical composition or make-up of the substance
New substances are formed with new properties
Not easily reversible
(Reversible only through chemical means or reactions)
Rust

6. Signs of Chemical Changes:
Tells you a
chemical change
occurred
Signs of Chemical Changes:
Formation of a gas
Formation of a precipitate
Change in color
Production of heat &/or light
Increase or decrease in mass

7. Examples: Physical Change Chemical Change Sublimation Freezing
Condensation
Evaporation
Pulverization (crush)
Solidification
Dissolving
Chemical Change
- Burning
- Neutralization
- Combustion
Corrosion (rusting)

8. Ex #1: 1. Melting Butter 4. Crushing Rock 2. Rusted Car
Which of the following are examples of physical changes?
1. Melting Butter
4. Crushing Rock
2. Rusted Car
5. Condensation
3. Dissolving Sugar in Tea
6. Burning Wood

9. Ex #3: Chemical Change Physical Change
Where did a chemical change occur? A physical change?
You carry out the following steps of an experiment & record your observations.
Ex #3:
1. You place a powder in a test tube
2. You heat the test tube. You notice that a colorless gas & a copper- colored liquid are produced.
3. You collect the copper-colored liquid & cool it. It becomes a solid.
Chemical Change
Physical Change

10. Ex #2: 1. Cooking an egg 4. Freezing Rain 2. Rotting food
Which of the following are examples of chemical changes?
1. Cooking an egg
4. Freezing Rain
2. Rotting food
5. Burning a candle
3. Sublimation of Dry Ice
6. Crumpling Paper

11. References Student Study Guide – Physical Science 416/436 - MEQ
Science Quest – Grenier, Daigle, Rheaume – 1998, Cheneliere
Animation Factory Clip Art
Microsoft Clip Art
Google Images