The surface tension of a liquid is the amount of energy required to increase the surface area of the liquid. Liquids have surface tension because the molecules on the surface are more attracted to each other than they are to the molecules in the air above them. This causes the surface of the liquid to act like a stretched elastic membrane.

Some examples of surface tension in everyday life include:

* The water droplets that form on a rainy day

* The way that insects are able to walk on water

* The way that oil and water separate in a salad dressing

* The way that soap bubbles form

* The way that paint drips from a brush

Surface tension is an important property of liquids that has a significant impact on their behaviour.