Question

what is an example of a physical change? having less ash than the paper that was burned to form it ice forming and then melting back into water rust having a different identity than the iron it forms on the irreversible reaction of vinegar and baking soda

Explanation:

A physical change is a change in which the substance's form or appearance changes, but its chemical composition remains the same. Burning paper is a chemical change (producing ash with a different chemical composition). Rusting of iron is a chemical change (new substance - rust). The reaction of vinegar and baking soda is a chemical change (produces new substances like carbon dioxide). Ice forming (water changing to solid - physical change) and then melting back (solid changing to liquid - physical change) involves only changes in state (from liquid to solid and back to liquid) without a change in chemical composition.

Answer:

Ice forming and then melting back into water.