Surface tension is a contractive tendency of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in the 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) to run on the water surface. This property is caused by cohesion of similar molecules, and is responsible for many of the behaviors of liquids.
Surface tension has the dimension of force per unit length, or of energy per unit area. The two are equivalent—but when referring to energy per unit of area, people use the term surface energy—which is a more general term in the sense that it applies also to solids and not just liquids.
In materials science, surface tension is used for either surface stress or surface free energy.
Read more about Surface Tension: Causes, Methods of Measurement, Thermodynamics, Data Table
Famous quotes containing the words surface and/or tension:
“See how peaceful it is here. The sea is everything. An immense reservoir of nature where I roam at will.... Think of it. On the surface there is hunger and fear. Men still exercise unjust laws. They fight, tear one another to pieces. A mere few feet beneath the waves their reign ceases, their evil drowns. Here on the ocean floor is the only independence. Here I am free.”
—Earl Felton, and Richard Fleischer. Captain Nemo (James Mason)
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—Stefan Zweig (18811942)