Long recognized in compounds, sodium was first isolated by Davy in 1807 by electrolysis of caustic soda.
Sodium is present in fair abundance in the sun and stars.
The D lines of sodium are among the most prominent in the solar spectrum. The most common compound is sodium chloride, but it occurs in many other minerals, such as soda niter, cryolite, amphibole, zeolite, sodalite, etc. It is a very reactive element and is never found free in nature. It is now obtained commercially by the electrolysis of absolutely dry fused sodium chloride. This method is much cheaper than that of electrolyzing sodium hydroxide, as was used several years ago.