This amazing experiment works on surface tension. Surface tension is a thin sheet or skin formed by water. Surface tension tightly holds the water molecules together. Thus, if the surface tension of the water remains undisturbed, it will be able to support the paper clip. Thus, the paper clip is not actually floating, it is simply being held on the water surface due to surface tension. Several insects such as grasshoppers and water spider use this “sheet” to walk across water.