Water
Water is an inorganic , transparent , tasteless , odorless , and nearly colorless chemical substance , which is the main constituent of Earth 's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent ). It is vital for all known forms of life , even though it provides no calories or organic nutrients . Its chemical formula is H 2 O, meaning that each of its molecules contains one oxygen and two hydrogen atoms , connected by covalent bonds . Two hydrogen atoms are attached to one oxygen atom at an angle of 104.45°. "Water" is the name of the liquid state of H 2 O at standard conditions for temperature and pressure . It forms precipitation in the form of rain and aerosols in the form of fog . Clou...