Absorption is a chemical or physical process by which an ion, atom, or molecule enters a gas, liquid, or solid. Adsorption is the physical process by which a liquid, gas, or suspended matter gathers on the surface of a substance.

Examples of Absorption

Incorrect: Solar radiation is adsorbed in the Earth’s atmosphere. Correct: Solar radiation is absorbed in the Earth’s atmosphere.

Examples of Adsorption

Incorrect: Gases are absorbed on the plane surfaces of glass. Correct: Gases are adsorbed on the plane surfaces of glass.

Tips to Remember

1. ‘B’ for Bulk: The ‘b’ in absorption can help you remember that it is a ‘bulk’ phenomenon, meaning it happens well beyond the surface! 2. Practice makes perfect: Quite an archaic suggestion, but it always works! Try writing down multiple examples of ‘absorption’ and ‘adsorption’ to grasp their meanings.