What explains the phenomena of wetting and non-wetting?

If a liquid is in contact with a solid, then there are two possibilities: 1) the molecules of the liquid are attracted to each other more strongly than to the molecules of the solid. As a result, the forces of attraction between the molecules of the liquid collect it into a droplet. This is how mercury behaves on glass, water on paraffin or “oily” surfaces. In this case, it is said that the liquid does not wet the surface; 2) molecules of a liquid are attracted to each other weaker than to molecules of a solid. As a result, the liquid tends to press against the surface and spreads over it. This is how mercury behaves on a zinc plate, water on clean glass or wood. In this case, it is said that the liquid wets the surface.