What is the best definition for the word adsorb?

The term "adsorb" refers to the process by which atoms, ions, or molecules from a gas, liquid, or dissolved solid adhere to a surface, creating a film or layer. The context of adsorption involves the accumulation of these particles onto a surface, which differentiates it from absorption, where one substance becomes incorporated into another.

Choosing the definition "accumulate" captures the essence of this process accurately, as it emphasizes the gathering or buildup of substances on a surface. The other options do not reflect the specific nature of the process; "divide" implies separation, "process" refers to a series of actions or steps taken to achieve a result, and "contain" involves holding something within limits, none of which accurately describes the act of adsorption.