* Chemical Change: A chemical change results in the formation of new substances with different chemical properties.

* Physical Change: A physical change alters the appearance or form of a substance but does not change its chemical composition.

How Rusting is a Chemical Change:

1. Reactants: Iron (Fe) reacts with oxygen (O2) in the presence of water (H2O).

2. Products: The reaction forms iron oxide (Fe2O3), commonly known as rust. Iron oxide has different properties than iron, including color, texture, and reactivity.

3. Irreversible: While you can remove rust, you cannot easily reverse the chemical reaction to get pure iron back.

In Summary: Rusting involves the formation of a new substance (iron oxide) through a chemical reaction. This makes it a chemical change, not a physical change.