What is the concept of water tension?

Surface tension is a physical effect, which makes the surface of liquid always try to get the smallest smooth area, just like it.

Just like an elastic membrane. To enlarge the surface area of a certain volume of liquid, it is necessary to do work on the liquid.

To enlarge the surface area of a certain volume of liquid, it is necessary to do work on the liquid. Surface tension is defined as the work done to expand the surface of a liquid divided by the area to be expanded. Therefore, surface tension can also be regarded as the density of surface energy. Because the surface of liquid is in contact with gas, the molecular distribution of surface layer is thinner than that in liquid, that is, the distance between molecules is larger than that in liquid. In the surface layer, because the distance between molecules is relatively large, the force between molecules shows attraction. If a dividing line MN is arbitrarily drawn on the liquid surface and the liquid surface is divided into two parts, the resultant force of the molecules on the left side of the liquid surface to the molecules on the right side of the liquid surface is gravitational force F 1. The resultant force of the molecules on the right side of the liquid surface acting on the molecules on the left side is gravity F2, and F 1 is equal in magnitude and opposite in direction to F2. The attractive force between different parts of a liquid surface is called surface tension. Under the action of surface tension, the liquid surface tends to shrink to the minimum.

The concept of defining the surface tension of a pair of liquids is described as follows: the attractive force between one surface layer and the other surface layer of any boundary line on the surface of a liquid is called surface tension.

The tangential component of the interaction force (attraction as much as possible) between the surface layer on one side of any boundary line of the liquid surface and the liquid on the other side (in fact, the surface layer on the other side is twice as thick as the surface layer) is called surface tension.

To enlarge the surface area of a certain volume of liquid, it is necessary to do work on the liquid. Surface tension is defined as the work done to expand the surface of a liquid divided by the area to be expanded. Therefore, surface tension can also be regarded as the density of surface energy.