Which one of the following is NOT applicable to the phenomenon of Adsorption?

It is an endothermic process

Adsorption: The phenomenon of higher concentration of any molecular species at the surface than in the bulk of solid is known as adsorption.

During adsorption, there is always a decrease in residual forces of the surface, i.e., there is decrease in the surface energy which appears as heat.

Adsorption, therefore, is invariably an exothermic process.