SymbolB A soft, brown, amorphous or crystalline nonmetallic element, extracted chiefly from kernite and borax and used in flares, propellant mixtures, nuclear reactor control elements, abrasives, and hard metallic alloys. Atomic number 5; atomic weight 10.811; melting point 2,300°C; sublimation point 2,550°C; specific gravity (crystal) 2.34; valence 3. See table at element.
bôr
n
, b
r
-r
k, bô-) —ADJECTIVE
