Gathers on the surface, as a layer of molecules

• Holds on a surface, as molecules
• Takes up onto the surface
• Causes to condense on a surface
• Gathers in a condensed layer
• Condenses on a surface
• Collects in condensed form
• What charcoal does to gases

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: adsorb)