Chemical Changes
A Chemical change occurs when:
- A new substance is formed
- It can not be reversed
When chemical changes occur the following can also be seen:
- Heat given off - Gas given off
- Light given off - Change in colour
Some example of chemical changes are:
- Cooking an egg, reason - The colour of the egg white changes and it can not be reversed.
- Milk going sour, reason - The colour changes, gas given off and it can not be reversed.
Complete the task below
Six of the images above are Chemical changes. Identify which are the Chemical changes and explain why it is.
Chemical Change
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Reason
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Frying egg
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It changes colour in can not change back
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Baking a cake
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It rises and can’t be unraised
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Batteries
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It runs out of life it can’t be returned
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Fire works
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It explodes and can’t be reversed
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Fire
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The wood burns and turns into ashes the ashes can’t be returned into wood
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Making pop corn
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It changes its shape it can’t turn back into its first shape
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Give 3 things to look for when deciding if something is a Chemical change:
- Change in colour
- eggs
- Batteries
