1. Matter Notes: Properties (Part 2)
WCHS Chemistry

2. Physical and Chemical Changes

3. Physical Change
Occurs when substances do not change their chemical identities!
Substances are not altered chemically
No new products are formed
Physical changes can usually be reversed!
Ex: dissolving, state changes,

4. Chemical Change
Occurs when a substance changes into/ becomes a different substance.
Chemical changes happen on a molecular level
*******Chemical changes are NOT reversible!

5. Evidence of Chemical Changes
A gas is produced (Ex: bubbles)
The temperature changes → by itself!
A substance disappears
A solid is formed
A color change occurs
A new odor is produced.

6. Chemical & Physical Properties
= Characteristics used to describe objects

7. Physical Property
Can be measured without changing the chemical composition of a substance
Ex: color, odor, shape, size, boiling, and freezing point.

8. Chemical Property
Describes a substance’s “potential” to undergo some chemical change
Ex: reactivity with water, pH, flammability.

9. Intensive & Extensive Properties

10. Intensive Property
Does NOT depend on the system size of the amount of material involved.
Ex: density, temperature, color, melting and boiling point.

11. Extensive Property
Does depend on the system size or the amount of material in the system.
Ex: Mass, volume, length