Chemical data for Nb - Niobium |


Atomic Number: 41
Atomic Weight: 92.9064
Element Type: Transition Metal
Crystal Structure: Cubic Body Centered
Melting Point: 2477.0°C = 4490.6°F = 2750.15 K
Boiling Point: 4744.0°C = 8571.2°F = 5017.15 K
Critical Temp: °C = °F = K
Atomic Radius: 2.08 Å (Å = Angstrom = 10-10 m)
Covalent Radius: 1.34 Å
Electronegativity: 1.6


(Niobe, daughter of Tantalus) Discovered in 1801 by Hatchett in an ore sent to Englandmore than a century before by John Winthrop the Younger, first governor of Connecticut.The metal was first prepared in 1864 by Blomstrand, who reduced the chloride by heating itin a hydrogen atmosphere. The name niobium was adopted by the International Union of Purand Applied Chemicstry in 1950 after 100 years of controversy. Many leading chemicalsocieties and government organizations refer to it by this name. Most metallurgists,leading metal societies, and all but one of the leading U.S. commercial producers,however, still refer to the metal as "columbium."


The element is found in niobite (or columbite), niobite-tantalite, parochlore, andeuxenite. Large deposits of niobium have been found associated with carbonatites(carbon-silicate rocks), as a constituent of parochlore. Extensive ore reserves are foundin Canada, Brazil, Nigeria, Zaire, and in Russia.