What causes iron to rust when exposed to air and moisture?

Explanation

Rust forms through oxidation, a chemical reaction in which iron reacts with oxygen and moisture in the air to form iron oxide. This process weakens metal structures over time, which is why iron and steel are often coated with paint, zinc through galvanization, or other protective layers. Stainless steel resists rusting because it contains chromium, which forms a protective oxide layer. Explore more Everyday Science MCQs on mcqstutor to keep practicing.