A process by which one substance combines with a second substance is called:

A process by which one substance combines with a second substance is called:

• A. Adsorption
• B. Dilution
• C. Neutralization
• D. Absorption

Answer: (D)

Absorption is the process where one substance is taken up into another substance, becoming part of its interior. This is why it best fits a scenario where a substance combines with a second substance in a way that the first is incorporated into the second, like a sponge soaking up a liquid or a solvent dissolving a solute. In HazMat work, this is the behavior you rely on when a material takes in a spill, so the term describes the internal uptake rather than just sticking to a surface. By contrast, adsorption is when molecules stick to the surface of a material without entering its interior—think dust collecting on a surface or vapors binding to activated carbon on the surface. Neutralization is a chemical reaction that forms new compounds (usually salts and water) and isn’t simply about combining into one substance, and dilution is about reducing concentration by adding more solvent, not about incorporation into the second substance.

Absorption is the process where one substance is taken up into another substance, becoming part of its interior. This is why it best fits a scenario where a substance combines with a second substance in a way that the first is incorporated into the second, like a sponge soaking up a liquid or a solvent dissolving a solute. In HazMat work, this is the behavior you rely on when a material takes in a spill, so the term describes the internal uptake rather than just sticking to a surface.

By contrast, adsorption is when molecules stick to the surface of a material without entering its interior—think dust collecting on a surface or vapors binding to activated carbon on the surface. Neutralization is a chemical reaction that forms new compounds (usually salts and water) and isn’t simply about combining into one substance, and dilution is about reducing concentration by adding more solvent, not about incorporation into the second substance.