Which term refers to the attachment of surfaces or molecules?

• A. Absorption
• B. Aphotic Zone
• C. Siliceous Ooze
• D. Adhesion

Answer: (D)

Adhesion is all about sticking at the boundary between substances. When surfaces or molecules experience attraction to each other, they attach at the interface, which is exactly what adhesion describes. This explains why a droplet of water will cling to glass or why organisms can cling to rocks in the marine environment. It’s different from absorption, which involves substances entering into the interior of a material rather than staying attached at the surface. Absorption would be like a sponge soaking up water, not simply having the surface hold onto it. The other terms don’t fit: the aphotic zone is a lightless depth, and siliceous ooze is a type of sediment composed of microscopic silica remains. So the correct concept is adhesion.