Water covers three-fourth of the Earth’s surface, with over 97% present in the oceans and less than 1% in freshwater streams. Water is also present in the atmosphere in solid form in the polar icecaps and as groundwater.
Water has many remarkable properties. It is sometimes referred to as ‘the universal solvent’, readily dissolving a wide range of chemical substances. It also acts as a fluid medium facilitating the dispersal of un-dissolved particulate matter.