Examples of corrosion include

(A) Rusting of iron
(B) Tarnishing of silver
(C) Green coating on copper and bronze
(D) Zinc coating on iron

Choose the correct answer from the options given below:

(A), (B) and (C) only

The correct answer is Option (3) → (A), (B) and (C) only

(A) Rusting of iron: This is the most common example of corrosion. It occurs when iron reacts with oxygen and moisture in the air to form hydrated iron(III) oxide ($Fe_2O_3 \cdot xH_2O$).

(B) Tarnishing of silver: Silver reacts with hydrogen sulfide ($H_2S$) or sulfur compounds in the air to form a thin black layer of silver sulfide ($Ag_2S$). This chemical deterioration is a form of corrosion.

(C) Green coating on copper and bronze: When copper or its alloys (like bronze) are exposed to moist air containing carbon dioxide, they react to form a green layer of basic copper carbonate ($CuCO_3 \cdot Cu(OH)_2$), also known as a patina. This is a classic example of corrosion.

(D) Zinc coating on iron: This process is called galvanization. It is not an example of corrosion itself; rather, it is a method used to prevent the corrosion of iron. The zinc acts as a protective barrier and a sacrificial anode.