a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
lamp in which an electric current passed through a tube of sodium vapor makes a yellow light; used is street lighting
lamp in which an electric current passed through a tube of sodium vapor makes a yellow light; used is street lighting
