Which of these is an example of a physical change?
sugar, when heated, producing carbon dioxide and water
solid ice, when heated, turning into liquid water
sodium, when exposed to chlorine, forming sodium chloride
aluminum, when heated in air, forming aluminum oxide

Solid ice, when heated, turning into liquid water

Option (b) is the correct answer.

Explanation:

A physical change can be observed when there is no change in the chemical composition of a substance.

Whereas if there occurs any change in the chemical composition of a substance then that change is known a chemical change.

When sugar is heated its chemical composition changes as it produces carbon dioxide and water.

Sodium on exposure to chlorine forms sodium chloride, therefore its composition will also change. Also, aluminum, when heated in air, forms aluminum oxide thus, chemical composition of aluminium will change.

But when solid ice is heated then it turns into liquid water, that is, only the state changes from solid to liquid and there is no change in the chemical composition of water which is in the form of ice here.

Thus, we can conclude that solid ice, when heated, turning into liquid water represents a physical change.