Physical and Chemical Changes

1
Physical and Chemical Changes
2
What is a Physical Change?

• A physical change alters the form of a substance,
  but does not change it to another substance
• In most cases, it can be reversed.

Example Melting ice Cutting paper
3
What is a Chemical Change?

• When a substance undergoes a chemical change, it
  is changed into a different substance with
  different properties. (irreversible)

Example Baking a Cake Rusty nail
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5 Signs of a Chemical Change

1. Color Change
2. Precipitation

5
5 Signs of a Chemical Change

1. Gas Production
2. Temperature Change

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5 Signs of a Chemical Change

1. Changes in Characteristic Properties (odor, light
   given off)

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Chemical or Physical Change?

• Toast burning?
• Chemical

8
Chemical or Physical Change?

• Rocket fuel burning?
• Chemical

9
Chemical or Physical Change?

• Sawing wood?
• Physical

10
Chemical or Physical Change?

• Metal rusting?
• Chemical

11
Chemical or Physical Change?

• Disappearing puddle?
• Physical