Niobium (Nb)

From Wikipedia, the free encyclopediaNiobium, formerly columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41. It is a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite. The name comes from Greek mythology:Niobe, daughter of Tantalus since it is so similar to tantalum.

Niobium in the periodic table

SymbolNb
Atomic number41
Group5
Period5
Blockd
Element categoryTransition Metal

Physical properties

Phase at STPSolid
Density8.57 g/cm3
Atomic weight92.9064 u
Melting point2750 K
2476.85 °C
4490.33 °F
Boiling point5017 K
4743.85 °C
8570.93 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.6
Electron affinity88.516 kJ/mol
Ionization energies
1652.1 kJ/mol
2 1380 kJ/mol
3 2416 kJ/mol
4 3700 kJ/mol
5 4877 kJ/mol
6 9847 kJ/mol
7 12100 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1
Electrons per shell2, 8, 18, 12, 1

History

Discovered1801
Discovered byCharles Hatchett