Water water, a substance composed of the chemical elements hydrogen and oxygen and existing in gaseous, liquid, and solid states. It is one of the most plentiful and essential of compounds. A tasteless and odourless ( without a smell) liquid at room temperature, it has the important ability to dissolve many other substances. Melting point: 0 °C Density: 997 kg/m³ Formula: H₂O Boiling point: 100 °C Molar mass: 18.01528 g/mol IUPAC ID: Oxidane Water Properties of water Water is an important component of our body . It constitutes about 65 % of the total body mass. Most of the reaction in the cell is carried out in aqueous medium (water). Water is made up of oxygen and two hydrogen atoms. Oxygen has a tendency to pull the electron towards itself. Due to this a dipole ( a pair of equal and oppositely charged or magnetized poles separated by a distance) is created in which each water molecule is surrounded by four other water molecules. Properties: Melting point Boiling points