What are the conditions for surface tension to take place?
Answer: Surface tension is a contractive tendency of the surface of a liquid that allows it to resist an external force. The main condition to observe various phenomena based on surface tension is the existence of the phase boundary between two phases, one of which is a liquid. For example, if the second phase is a gas, we can observe such phenomena as bubbles, breakup of streams into drops etc.; if the second phase is a solid body, we can observe such phenomena as flotation of small objects with density, higher than density of the liquid, capillary action, spherical droplets of liquid on nonwettable surfaces etc.