The importance of common salt to animal nutrition has been recognized since prehistoric times. On a volume basis, it is the cheapest of all metals. Sodium metal should be handled with great care. It should be kept in an inert atmosphere and contact with water and other substances with which sodium reacts should be avoided. Improve structure of certain alloys, to descale metal, to purify molten metals, in reduction of org esters.
Heated sodium is spontaneously flammable in air.
Sodium, reduced to fine state of subdivision, when mixed with lead oxide ignites spontaneously. D-lines of sodium are among most prominent in solar spectrum. 6th most abundant element on earth most abundant of alkali group of metals most common cmpd is sodium chloride other minerals soda niter, cryolite, amphibole, zeolite, sodalite.