Why does surface tension exist

Why is it so important? Ask Question. Asked 2 years, 9 months ago. Active 2 years, 9 months ago. Viewed 1k times. Why does a fluid has to bear surface tension? And is surface tension dependent on properties like density and viscosity?

Improve this question. Gamira Gamira 1 1 gold badge 6 6 silver badges 9 9 bronze badges. This seems a bit subjective. In some instances it is useful spilling is less probable , in others it is not exact measurements. Surface tension in water might be good at performing tricks, such as being able to float a paper clip on its surface, but surface tension performs many more duties that are vitally important to the environment and people.

Find out all about surface tension and water here. Surface Tension: "The property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of its molecules. It seems to defy the laws of physics, but a paper clip made of steel can indeed float on the water surface. The high surface tension helps the paper clip - with much higher density - float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.

The molecules at the surface of a glass of water do not have other water molecules on all sides of them and consequently they cohere more strongly to those directly associated with them in this case, next to and below them, but not above.

It is not really true that a "skin" forms on the water surface; the stronger cohesion between the water molecules as opposed to the attraction of the water molecules to the air makes it more difficult to move an object through the surface than to move it when it is completely submersed.

Source: GSU. The cohesive forces between molecules in a liquid are shared with all neighboring molecules.

Those on the surface have no neighboring molecules above and, thus, exhibit stronger attractive forces upon their nearest neighbors on and below the surface. Surface tension could be defined as the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of the water molecules.

Surface tension in water owes to the fact that water molecules attract one another, as each molecule forms a bond with the ones in its vicinity. At the surface, though, the outmost layer of molecules, has fewer molecules to cling to, therefore compensates by establishing stronger bonds with its neighbors, this leading to the formation of the surface tension.

Water molecules want to cling to each other. At the surface, however, there are fewer water molecules to cling to since there is air above thus, no water molecules. This results in a stronger bond between those molecules that actually do come in contact with one another, and a layer of strongly bonded water see diagram. This surface layer held together by surface tension creates a considerable barrier between the atmosphere and the water.

In fact, other than mercury, water has the greatest surface tension of any liquid. However, liquids, like gases, are fluids, meaning that their molecular units can move more or less independently of each other.

Whereas the volume of a gas depends entirely on the pressure, the volume of a liquid is largely independent of the atmospheric pressure. Therefore, gases are compressible while liquids are very nearly not. The molecules in a sample of a liquid that find themselves fully in the interior volume are surrounded by other molecules and interact with them based on the attractive intermolecular forces that are present for molecules of this type. However, the molecules at the interface with another medium usually air do not have other like molecules on all of their sides namely, on top of them , so they cohere more strongly to the molecules on the surface and immediately below them.

The result is a surface film which makes it more difficult for an object to pierce through the surface than for it to move once submerged in the sample of liquid. Therefore, the cohesive forces result in the phenomenon of surface tension. Surface tension is responsible for the shape of a liquid droplet.

Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. The table below demonstrates values of surface tension obtained for different liquids at various temperatures.

Experimental Surface Tension Values. Edited by Anne Marie Helmenstine, Ph. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. Share Flipboard Email.

Table of Contents Expand. Causes of Surface Tension. Examples of Surface Tension. Anatomy of a Soap Bubble. Pressure Inside a Soap Bubble. Pressure in a Liquid Drop. Contact Angle. Quarters in a Full Glass of Water. Floating Needle. Put Out Candle with a Soap Bubble. Motorized Paper Fish. Andrew Zimmerman Jones. Math and Physics Expert.

Andrew Zimmerman Jones is a science writer, educator, and researcher. He is the co-author of "String Theory for Dummies.