Which of the following is an example of a chemical change?

Iron rusting is a prime example of a chemical change because it involves a reaction between iron and oxygen in the presence of moisture, resulting in the formation of iron oxide, commonly known as rust. This process alters the chemical composition of the iron, creating a new substance that has different properties compared to the original material. Unlike physical changes, which may involve alterations in state or appearance without a change in chemical identity, rusting fundamentally transforms the iron into a different compound.

For context, melting ice, boiling water, and breaking glass are all examples of physical changes. Melting ice involves a change in state from solid to liquid without changing the chemical structure of water. Boiling water is the transition from liquid to gas, again without changing the chemical composition. Breaking glass changes the appearance and structure of the glass but does not alter its chemical makeup.