1. Notes 2.1 Physical and Chemical Properties and Changes

2. A.1 Properties Make the Difference
Every substance has characteristic properties that distinguish it from other substances
Physical properties
Described by senses - Color, density, odor, touch
Can be determined without altering the chemical makeup of the material
Also influence use via ability to undergo changes
Examples - melting, boiling, bending

3. A.1 Properties Make the Difference
Physical change
Material remains the same chemically, but
the form is different
Usually reversible
Ex. Tearing, cutting, bending, filtering, melting boiling

4. A.1 Properties Make the Difference
Chemical change
When a substance changes into one or more new substances
Not reversible
Rusting- tendency of a metal to form an oxide
Evidences for a chemical change
Formation of gas
Formation of a
precipitate (solid)
Permanent color change
Production of heat
and light

5. A.1 Properties Make the Difference
Chemical properties
Relate to any kind of chemical changes
Flammability, Reactivity, Oxidizer