[soh-dee-uh
m] 
| 1. | Chemistry. a soft, silver-white, metallic element that oxidizes rapidly in moist air, occurring in nature only in the combined state, and used in the synthesis of sodium peroxide, sodium cyanide, and tetraethyllead: a necessary element in the body for the maintenance of normal fluid balance and other physiological functions. Symbol: Na; atomic weight: 22.9898; atomic number: 11; specific gravity: 0.97 at 20°C. |
| 2. | Medicine/Medical, Pharmacology. any salt of sodium, as sodium chloride or sodium bicarbonate, present in or added to foods or beverages as a seasoning or preservative and used in many pharmaceutical products as an antacid, anticoagulant, or other agent. |
| so·di·um (sō'dē-əm) n. Symbol Na A soft, light, extremely malleable silver-white metallic element that reacts explosively with water, is naturally abundant in combined forms, especially in common salt, and is used in the production of a wide variety of industrially important compounds. Atomic number 11; atomic weight 22.99; melting point 97.8°C; boiling point 892°C; specific gravity 0.971; valence 1. See Table at element. [sod(a) + -ium.] |
sodium so·di·um (sō'dē-əm)
n.
Symbol Na
A soft, light, highly reactive metallic element that is naturally abundant, especially in common salt. Atomic number 11; atomic weight 22.99; melting point 97.7°C; boiling point 883°C; specific gravity 0.971; valence 1.