Brownish film formed on iron when left in open is called

Correct answer: Rust

Explanation: ✅ Correct Answer: D. Rust 📚 Explanation: Rusting is a chemical reaction that occurs when iron is exposed to moisture and oxygen in the air. This process results in the formation of a reddish-brown flaky substance called hydrated iron oxide. Rust weakens the iron over time and eventually causes it to disintegrate. It can be prevented by painting, oiling, or galvanizing the metal surface.