What process can cause metals to rust?

Rusting is a specific type of oxidation that occurs when iron or its alloys, such as steel, react with oxygen and moisture in the environment. The chemical reaction that leads to rust involves iron, water (in the form of moisture), and oxygen, which combine to form iron oxide, commonly known as rust. This process can be accelerated in the presence of salts and other electrolytes, which facilitate the transfer of electrons during the oxidation reaction.

Oxidation is the correct answer because rusting fundamentally relies on the transfer of electrons from the iron to oxygen, resulting in the formation of iron oxide. It’s a redox reaction where the iron is oxidized, losing electrons, while the oxygen is reduced, gaining those electrons.

In contrast, while weathering refers to the breakdown of rocks and minerals due to environmental factors, it does not specifically address the chemical processes involved in rusting. Condensation and evaporation involve changes in the state of water but are not directly responsible for the formation of rust on metals. Thus, oxidation is the primary chemical process responsible for the rusting of metals, making it the correct choice in this context.