Final answer:
A hammer smashing through a piggy bank represents a physical change, not a chemical change, because the piggy bank's material remains chemically identical before and after the smashing.
Step-by-step explanation:
When a hammer smashes through a piggy bank, it is not a chemical change but rather a physical change. A chemical change is a reaction where the chemical composition of the original substance is changed, producing one or more different kinds of matter. Examples of chemical changes include rust forming on iron due to oxidation, the combustion of substances resulting in new compounds, and a metal such as zinc reacting with sulfur to form zinc sulfide when heated.
Physical changes, on the other hand, involve changes in the physical form or properties of a substance without altering its chemical structure. Breaking a piggy bank is similar to other physical changes like ice melting, water boiling, or a mirror breaking. In these cases, no new substances are formed; the material involved, be it glass, water, or ceramic from the piggy bank, remains chemically identical before and after the change.