Physical and Chemical Changes

What am I doing here? Why should I care?

By the end of this lesson you will be able to:

1. Summarise the main difference between physical and chemical changes

2. Identify examples of physical and chemical change

Physical Changes

The key feature of a physical change is that no new substance is produced during the change. Physical changes include a change in shape or form, expansion and contraction, a change of state (solid, liquid or gas) or mixing substances together. The physical properties of the substance may change but no new substance is formed. For this reason, physical changes are often reversible.

Physical Changes

• No new substance is produced

• Change in shape, state (solid, liquid or gas) or mixing substances together

• Are often reversible

Chemical Changes

If a new substance has been produced, then a chemical change has occurred. The new substance formed in a chemical change could be a solid, liquid or gas.

Chemical Changes

• New substance is produced and it may be a solid, liquid or gas

• You may observe:

• Colour change

• Smell a gas or see bubbles

• New solid formed (precipitate)

• Light or heat is produced

1. Cut out the table and small rectangles

2. Glue the table into your books

3. Sort the rectangles and glue them into the correct column

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Task: Chocolate Factory