Physical changes are, in general, reversible, but only some chemical changes are reversible while others are irreversible.
AUS-e-TUTE has just added new resources to help you classify changes as reversible or irreversible.
AUS-e-TUTE members should log-in to use the new resources.
If you are not an AUS-e-TUTE Member you can access a "free-to-view" tutorial at https://www.ausetute.com.au/reversible.html