Physical changes are changes in which there are no changes in the internal structure of substances. When there is a chemical change a chemical reaction is involved and the internal structure of the substance changes.
Of the four options that give us the first two: The oxidation of steel and burned paper represents an oxidation and combustion reaction respectively, so they correspond to chemical changes.
The second two options are phase changes, there is no chemical reaction and therefore the internal structure of the substances does not change. So the options to select will be:
Answer:
Acetone evaporating
Ice melting