What is surface tension

Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, 
in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some 
insects (e.g. water striders) and even reptiles (basilisk) to run on the water surface. This property is caused by cohesion 
of like molecules, and is responsible for many of the behaviors of liquids..