sorption

thumb|500px|Gas–liquid absorption (a) and liquid–solid adsorption (b) mechanism. Blue spheres are solute molecules.

Sorption is a physical and chemical process by which one substance becomes attached to another. Specific cases of sorption are treated in the following articles: Absorption: "the incorporation of a substance in one state into another of a different state" (e.g., liquids being absorbed by a solid or gases being absorbed by a liquid); Adsorption: The physical adherence or bonding of ions and molecules onto the surface of another phase (e.g., reagents adsorbed to a solid catalyst surface); Ion exchange: An exchange of ions between two electrolytes or between an electrolyte solution and a complex.