Sodium is a chemical element, typically found as a solid in its elemental form. It has the chemical symbol Na (from the Latin natrium), atomic number (number of protons) Z = 11, and a standard atomic weight of 22.989770 g/mol.
Sodium is considered to be a member of the "alkali metal" class of elements. At a pressure of 101.325 kPa, it has a boiling point of 883 °C, and a melting point of 97.8 °C. In solid form, its density is slightly less than that of water at 0.968 g/cc.
It is easily oxidized to the +1 oxidation state and forms many salts. Elevated sodium levels in humans may lead to high blood pressure and other complications. The pure metal reacts violently with water.