Na2TeO3, or sodium tellurite, is an inorganic compound composed of sodium, tellurium, and oxygen. It typically appears as a white or yellowish crystalline solid and is soluble in water. Sodium tellurite is often used in laboratories and industrial applications, particularly in the synthesis of other tellurium compounds. In biological contexts, Na2TeO3 has been studied for its potential effects on cells and microorganisms. It can act as an antimicrobial agent and has been investigated for its role in various biochemical processes. However, caution is advised due to its toxicity at higher concentrations.