The process ofcorrosion ofiron is known as rusting. Rust appears to be a hydrated ferricoxide `Fe_2O_3, xH_2O,` Both `O_2 & H_2O` are required for rusting. Iron can be protected from the rusting by use of following compounds.
i) Applying paints, lacquers and enamells on the surface ofiron ii) By forming a firm and coherent protective coating of ferroroferric oxide. This is done by passing steam over hot iron
iii) By coating a thin film of Zinc, Tin, Nickel, chromium, aluminium etc, on the surface of iron If plated with Zinc, the reaction of products of Zinc with `O_2` and `H_2O` form a coating which sticks to the surface and there by protects iron
Zinc protects iron from corrosion because

Options

A. It is an active metal
B. A sticky coating is formed on its surface on exposure to air
C. It is not affected by atmosphere
D. It has lower oxidation potential than iron

Answer

B

Explanation

Zno layers , form on Fe