REVERSIBLE AND IRREVERSIBLE CHANGE
An irreversible change is an change that can’t be changed back like.
Rust, fried egg, burning paper, cooking meat, cutting up a carrot, age.
A reversible change is a change that can be undone like.
Freezing water, heating or boiling water .melting wax ,ice ,chocolate and metal.
As you may have notices these are all substances and materials.