(So named (Greek Niobe) in 1844 by Heinrich Rose because of its close relationship with tantalum) A gray or white, metallic chemical element, somewhat ductile and malleable, used in steel alloys, superconducting alloys, in jet engines and rockets, etc.

Symbol: Nb
Atomic number: 41
Atomic weight: 92.90638
Density (at room temperature and pressure): 8.57 g/cc
Melting point: 2,468°C
Boiling point: 4,740°C
Valence: +3, +5
Ground state electron configuration: [Kr]4d45s1

Symbol: Nb
Atomic Number: 41
Atomic Weight: 92.9064
Boiling Point: 5015 K
Melting Point: 2742 K
Density at 300K: 8.57 g/cm3
Covalent radius: 1.34
Atomic radius: 2.08
Atomic volume: 10.80 cm3/mol
First ionization potental: 6.88 V
Specific heat capacity: 0.265 Jg-1K-1
Thermal conductivity: 53.7 Wm-1K-1
Electrical conductivity: 6.6 106Ω-1m-1
Heat of fusion: 26.9 kJ/mol
Heat of vaporization: 690.1 kJ/mol
Electronegativity: 1.6 (Pauling's)

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Ni*o"bi*um (?), n. [NL., fr. L. & E. Niobe.] Chem.

A later name of columbium. See Columbium.


© Webster 1913.

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