1. Unit 1: Exploring Matter
Section 1.3: Physical and Chemical Changes

2. Physical Change
In a physical change, the substance involved remains the same.
The only thing that can change in a physical change is the substance’s state.
For example, what happens when the wax from a melted candle cools?
It turns back into a solid

3. Chemical Change
In a chemical change, the original substance is changed into one or more different substances.
The new substances have different properties from the original substance.
There are 5 clues you should look for in any chemical change:
A new colour appears
Bubbles of gas are formed
Heat or light is given off
A solid material (called a precipitate) forms in a liquid
The reaction can not be reversed

4. What change is described by each of the following statements?
A glow stick begins to glow.
Water is boiled.
An egg is fried on a stove.
Wax from a candle melts.
A lollipop melts in the sun.
An iron nail rusts in the rain.
Blood permanently stains your shirt.
Milk left outside goes sour.
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