Final answer:
Iron rusting is a chemical change because it results in iron oxide, which has different properties than metallic iron, indicating that new chemical bonds have formed.
Step-by-step explanation:
The type of change iron rusting represents is a chemical change. When iron reacts with oxygen and moisture in the air, it forms iron oxide, commonly known as rust. This process is a chemical reaction because it involves the breaking of bonds between iron (Fe) and the formation of new bonds in the compound iron oxide (Fe2O3). The properties of rust are distinct from those of the original iron, which indicates that a chemical change has occurred. Examples that support iron rusting as a chemical change include the color change from grey to orange, and the fact that the rusted iron has different properties from the metallic iron it once was. Rust formation is irreversible under normal conditions, which further confirms it as a chemical change.