H2O is the chemical formula for water, which is an inorganic compound). Each molecule of water contains two atoms of hydrogen (H) joined to a single atom of oxygen (O) . Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is vital for all known forms of life, despite not providing food energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45° . Water is the major constituent of the fluids of all known living organisms, and it acts as a solvent.