In 1807, English chemist Humphry Davy discovered elemental sodium by isolating it from sodium hydroxide through electrolysis. In nature, sodium is never found in elemental form – only in compounds.
Sodium is an alkali metal that has the atomic number 11. Its chemical symbol is Na, which originates from the Latin word "natrium" for sodium carbonate. Sodium is silvery-white and is a solid at room temperature. However, it is a soft metal. It does burn in air, producing a yellow flame.
Sodium is useful in the production of sodium cyanide, titanium and esters. It also forms many compounds, including sodium chloride, borax and soda ash. In the form of sodium vapor, it is used in efficient streetlights that give off a yellow light.