Reversible and Irreversible Changes - KS2

This is a complete practical lesson for lower KS2 on the difference between reversible and irreversible changes. The lesson begins with an open-ended ‘odd one out’ activity intended to engage children’s deeper thinking and elicit appropriate scientific vocabulary and verbal reasoning.
Depending on your school’s health and safety policy, you may or may not be able to do the very first teacher demonstration, where you burn a small amount of methylated spirit in a plate (then show them the empty plate after it has burned away!) If not, videos can easily be found on YouTube.

For the 3 child-led practical parts of the lesson you will need:

• olive/sunflower/vegetable oil
• vinegar (any)
• sand
• filter paper
• funnels
• Alka-Seltzer tablets (one per pair) or similar

There is then a short activity to finish off with - differentiated three ways and with an open-ended extension question to keep any ‘fast finishers’ busy! The plenary activity challenges pupils to use what they have learned to discuss whether a real-world chemical change is reversible or irreversible. Give the blue cards to one partner and the yellow ones to the other. The partners will then have to work together to arrive at a conclusion.