Question

Ciara’s bike has rusted, which means that the iron in the metal changed to rust.

What has occurred?

an energy formation
an exothermic reaction
a chemical reaction
a precipitate formation

Answer 1

What has occurred is **a chemical reaction**. Rusting is a process where iron reacts with oxygen and moisture in the environment, resulting in iron oxide, commonly known as rust. This process involves a change in the chemical composition of the material, indicating that a chemical reaction has taken place.