atomic number 11, Na, sodium - 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)

mineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition

common salt, sodium chloride - a white crystalline solid consisting mainly of sodium chloride (NaCl)