Answer the following question:
Corrosion is the progressive of metals by the action of air, moisture or a chemical reaction (such as an acid) on their surface is called corrosion.
Example: When is exposed to moist air for an extended period, its surface acquires a coating of a , flaky substance called rust. Rust is mainly hydrated iron (III) oxide.
\(4Fe\) + \(3O_2\) + \(xH_2O\) → \(2Fe_2O_3.xH_2O\)