ScienceWalking on Water
Well maybe not by humans, when it’s a liquid, but it is possible for water to be walked on! Water has high surface tension meaning that small insects and bugs etc can walk on it!
Surface Tension
Not as impressive as a human walking on it but water tension is important for other things too. Plants require a high surface tension to allow water to be transported through the xylem. Water tension occures because of the forces acting upon molcules to hold them together, those at the edge are pulled inwards by the other molecules deeper into the water.
Have you ever seen a drop of water, or a bead of water on the grass? This occurs because of surface tension, this is also the reason for soap bubbles!
Surface Tension results from the polar nature of the water molecule which is discussed further in "In Solution"
Refrences
Google Definition of Xylem
http://www.google.co.uk/search?hl=en&q=define%3Axylem&btnG=Search&meta=
Wikipedia Article on Surface Tension
http://en.wikipedia.org/wiki/Surface_tension