What caused surface tension in water?

Answer 1

Simple Answer:

Surface tension is a consequence of the cohesive forces that keep the molecules all together. The molecules in water are attracted to each other by electrostatic forces. The essential point is that the water molecules on the surface are not attracted to the air molecule as much as to the other water molecule at the side and below it; this causes the water body want to reduce the surface area as much as possible. When something pushes to the surface slightly, this cause the surface area bigger and the cohesion forces try to minimize that, causing the tension we can observe.

Same Answer Said Differently:

Water has a somewhat higher surface tension than many other liquids because

the disruption of the forces between molecules at the surface weakens the molecular attraction significantly and the molecular forces were rather large to begin with, so the energy lost in forming the surface is large.

Surface tension is the force that resists deformation of a surface of a liquid. (Solids have this too, but that is more complex.) The cohesive forces in a liquid minimize the energy of the liquid by minimizing the surface area. It take force to overcome this cohesion and that results in surface tension.

Water molecules are special in that they have strong dipolar forces and the force of attraction therefore depends substantially on the orientation of the molecule relative to one another. The surface restricts the number and orientation of neighboring molecules, costing energy and creating significant surface tension.

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Surface tension in water is caused by molecules pulling equally in every direction to create a net force of zero and preventing items to submerge.