What are irreversible changes?

This week, I would like you to explore more materials and find out about irreversible changes to materials.

Watch resource 1 to give you some background and refresh your memory.

1. https://www.bbc.co.uk/bitesize/topics/zcvv4wx/articles/z9brcwx - irreversible changes

Find definitions for these words: reaction, reactant, substance, product, solid, liquid and gas

     2. https://www.bbc.co.uk/bitesize/clips/z9wkjxs - the chemistry of cooking

Have a go at some of the irreversible changes of your own (see the 2 slides below), as well as following a recipe to mix and bake cakes or biscuits. Are these chemical changes reversible or irreversible?

Use the correct scientific vocabulary to describe the changes you see when you mix milk and vinegar:

reaction, reactant, substance, product, solid, liquid and gas

Research and explain how casein plastic has been used commercially.

 

 

Extra challenges:

Find out about scientists who have used chemical changes to create useful new materials? Good examples include Spencer Silver or John McAdam as a starting point.

Irreversible changes don’t always create useful new materials. Investigate the conditions that cause rust to form – an unhelpful irreversible change.  Can you research any other examples of where and when irreversible changes are unhelpful?