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Niobium

Author: Robert Husted, Mollie Boorman

Atomic Number 41
Atomic Symbol Nb
CAS ID No. 7440-03-1
Atomic Weight 92.9060 amu
Electron Configuration [Kr] 4d4 5s1
Melting Point 2467.0 C
Boiling Point 4744 C
Density 8.550 g/cm3
History

(Named after Niobe, the daughter of Tantalus) Discovered in 1801 by Hatchett in an ore sent to England.  The metal was first prepared in 1864 by Blomstrand, who reduced the chloride by heating it in a hydrogen atmosphere. The name niobium was adopted by the International Union of Pure and Applied Chemicstry (IUPAC) in 1950 after 100 years of controversy. Many leading chemical societies 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."

Sources
Ref.: Wikimedia Commons, user Dnn87

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

Properties

Niobium is a shiny, white, soft, and ductile metal, and takes on a bluish cast when exposed to air at room temperatures for a long time. The metal starts to oxidize in air at 200C, and when processed at even moderate temperatures must be placed in a protective atmosphere.

Uses

Niobium is used in arc-welding rods for stabilized grades of stainless steel. Thousands of pounds of niobium have been used in advanced air frame systems such as were used in the Gemini space program. The element has superconductive properties; superconductive magnets have been made with Nb-Zr wire, which retains its superconductivity in strong magnetic fields. This type of application offers hope of direct large-scale generation of electric power. Niobium is also commonly used for jewelry. 

Isotopes

Eighteen isotopes of niobium are known. The metal can be isolated from tantalum, and prepared in several ways.




Last Update: 2011-02-16