Adsorption is a surface phenomenon.
A.True
B.False

Hint: Adsorption is a phenomenon in physical chemistry. This phenomenon is basically used in terms of solids. In this phenomenon molecules of the species remain intact at the surface, and it is defined in terms of concentration at the bulk part of the solid.

Complete step by step answer:
-Now, let us discuss the adsorption phenomenon step by step.
-As we already mentioned this term is used in physical chemistry.
-If we talk about the solids; as we know there are unbalanced forces on the surface of a solid, or a liquid.
-Now, due to this extra or we can say additional forces, the surface of solid shows a tendency to attract the molecules of other species on the surface.
-Thus, we know these molecules will remain on the surface, and it will lead to the increase in the concentration at the surface.
-So, adsorption can be defined as the phenomenon when there is an increase in the concentration at the surface rather than bulk part of the solid material.
-Therefore, adsorption property is mostly exhibited by the solids. As when we divide a solid molecule; there is an increase in surface area.
-If we talk about the examples then we can say charcoal, clay exhibits the adsorption property to a great extent.
-In the last we can conclude that the adsorption is a surface phenomenon.
Thus, the correct option is A.

Note:
There should be no confusion between the terms adsorption, and absorption. We have already discussed the adsorption phenomenon. Let us discuss the absorption phenomenon.
-In the absorption process, we can say that particles are uniformly distributed throughout the solid, or a liquid surface.
-Absorption just represents the physical phenomenon; whereas adsorption represents physical as well as chemical phenomenon.