This phenomenon is known as surface tension, and water has the highest surface tension of all common liquids. When water evaporates, it absorbs considerable amounts of heat. Water therefore acts as a buffer against temperature changes and keeps the earths climate from rapidly fluctuating. This allows for many free radicals to be available to the chemistry of life. Water is very dense, some 800 times denser than air.
Water absorbs light differentially.
S eawater Seawater is pure water plus dissolved solids and gases. The dissolved solids come from 'weathering' processes of the continental land masses rocks being dissolved by rain water and flowing out to sea with the rivers. The gases come from the atmosphere. As water is a universal solvent, many different compounds are dissolved in it. A 1kg sample of saltwater contains 35 g of dissolved compounds, including inorganic salts, organic compounds from living organisms, and dissolved gasses.