1 Answer | Add Yours
In physics it is said that water "wets" the walls of a glass tube (or otherwise explained it forms a concave meniscus when poured into a glass tube). Suppose you have a molecule of water that is located at the interface of water with the glass. The forces of interaction of this molecule with the molecules of glass (adhesion forces) are higher than the forces of interaction with the other water molecules inside the liquid (cohesion forces). This way the angle of contact of the surface layer of the water with the solid makes an angle bigger than 90 degrees and the surface meniscus of water becomes concave. The same phenomena happens when a drop of water is on the skin. The angle of contact of the water surface with the skin is bigger than 90 degrees. (in the case of mercury the adhesion forces are smaller than the cohesion forces and the angle of contact with a solid is smaller than 90 degrees; mercury does not wet the surfaces)
This is why water feel wets. Therefore the correct answer is a) Adhesion.
We’ve answered 319,639 questions. We can answer yours, too.Ask a question