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)
同义词：sodium, Na, atomic number 11
详细解释：
NASabbr.（略语） National Academy of SciencesNational Academy of Sciencesnaval air stationnaval air station