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Week 4


This lesson we will focus on irreversible changes. Irreversible changes are all around your house- mainly your kitchen. An irreversible change is where the material cannot be returned to its original form. Examples of irreversible changes are heating, mixing, burning and rusting

In most cases a new material is formed. Sometimes these new materials are useful to us.


Heating can cause an irreversible change. For example you heat a raw egg to cook it. The cooked egg cannot be changed back to a raw egg again.


Mixing substances can cause an irreversible change. For example, when vinegar and bicarbonate of soda are mixed, the mixture changes and lots of bubbles of carbon dioxide are made. These bubbles and the liquid mixture left behind, cannot be turned back into vinegar and bicarbonate of soda again.


Burning is an example of an irreversible change. When you burn wood you get ash and smoke. You cannot change the ash and smoke back to wood again.




There will be no answers uploaded to parent hub as this is your own observations. Please remember to send us pictures of your experiment on Skype!