Cool Science Experiments for Kids: Water's Skin & Surface Tension

Water's surface tension is characterized by an elastic-type sheet on the edge of the liquid. In physics, this phenomenon is known as water's skin, as the thin layer of “skin” allows certain insects, small metal objects and other minuscule things to seemingly walk on water. A paper clip, for example, may float on the top layer of water calmly, causing a capillary action. When two bodies of water form a layer of so-called skin between them, it is called interface tension. Though skin tension is relatively easy to observe in the home or classroom, its causes are slightly more complicated. The equally powerful attraction between neighboring liquid molecules to each other in all directions results in an overall equality of force (net force zero). The liquid molecules eventually push themselves together until balancing against the resistance of the liquid. The result is water skin!

It is easy to see why such a phenomenon would be interesting to kids, especially children with any sort of interest in science or biology. While the concepts of molecule interaction, zero force and energy states might be a little beyond an elementary school science fair's scope, the basic idea of water's capabilities and naturally prepared access to animals and insects that rely on it as a habitat is certainly worth the time. Learn how to duplicate this natural phenomenon in this free video clip series with our expert as he demonstrates the occurrence of water skin or skin tension, and shows you and your children how to prepare such a demonstration for a science class, science fair or class project.