Surface Tension

Surface tension is a property of the surface of a liquid. It is what causes the surface portion of liquid to be attracted to another surface, such as that of another portion of liquid. Surface tension is caused by cohesion (the attraction of molecules to like molecules). Since the molecules on the surface of the liquid are not surrounded by like molecules on all sides, they are more attracted to their neighbors on the surface.

Examples of Surface Tension

Water beading on a leaf

• Beading of rain water on the surface of a waxed automobile. Water adheres weakly to wax and strongly to itself, so water clusters into drops. Surface tension gives them their near-spherical shape, because a sphere has the smallest possible surface area to volume ratio.

Source:http://en.wikipedia.org/wiki/Surface_tension