Niobium

Niobium,  ₄₁Nb

General properties
Name, seembol	niobium, Nb
Appearance	gray metallic, bluish whan oxidised
Pronunciation	nəiˈobeəm ny-OH-bae-əm; umwhile kəˈɫʌmbeəm kə-LUM-bae-əm
Niobium in the periodic cairt
V ↑ Nb ↓ Ta zirconium ← niobium → molybdenum
Atomic nummer (Z)	41
Group, block	group 5, d-block
Period	period 5
Element category	transeetion metal
Staundart atomic wicht (±) (Ar)	92.90637(2)
Electron configuration	[Kr] 4d4 5s1
per shell	2, 8, 18, 12, 1
Pheesical properties
Phase	solid
Meltin pynt	2750 K ​(2477 °C, ​4491 °F)
Bylin pynt	5017 K ​(4744 °C, ​8571 °F)
Density near r.t.	8.57 g/cm3
Heat o fusion	30 kJ/mol
Heat o vapourisation	689.9 kJ/mol
Molar heat capacity	24.60 J/(mol·K)
vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2942 3207 3524 3910 4393 5013
Atomic properties
Oxidation states	5, 4, 3, 2, -1 (mildly acidic oxide)
Electronegativity	Pauling scale: 1.6
Atomic radius	empirical: 146 pm
Covalent radius	164±6 pm
Miscellanea
Creestal structur	​body-centred cubic (bcc)
Speed o soond thin rod	3480 m/s (at 20 °C)
Thermal expansion	7.3 µm/(m·K)
Thermal conductivity	53.7 W/(m·K)
Electrical resistivity	152 n Ω·m (at 0 °C)
Magnetic orderin	paramagnetic
Young's modulus	105 GPa
Shear modulus	38 GPa
Bouk modulus	170 GPa
Poisson ratio	0.40
Mohs haurdness	6.0
Vickers haurdness	1320 MPa
Brinell haurdness	736 MPa
CAS Nummer	7440-03-1
History
Diskivery	Charles Hatchett (1801)
First isolation	Christian Wilhelm Blomstrand (1864)
Recognised as a distinct element by	Heinrich Rose (1844)
Maist stable isotopes o niobium
iso NA hauf-life DM DE (MeV) DP 91Nb syn 6.8×102 y ε - 91Zr 91mNb syn 60.86 d IT 0.104e 91Nb 92Nb syn 10.15 d ε - 92Zr γ 0.934 - 92Nb syn 3.47×107y ε - 92Zr γ 0.561, 0.934 - 93Nb 100% - (SF) <0.943 93mNb syn 16.13 y IT 0.031e 93Nb 94Nb syn 2.03×104 y β− 0.471 94Mo γ 0.702, 0.871 - 95Nb syn 34.991 d β− 0.159 95Mo γ 0.765 - 95mNb syn 3.61 d IT 0.235 95Nb
Decay modes in parentheses are predicted, but hinna been observed yet

Niobium, umwhile columbium, is a chemical element wi the seembol Nb (umwhile Cb) an atomic nummer 41. It is a saft, grey, ductile transeetion metal, whilk is aften foond in the pyrochlore mineral, the main commercial soorce for niobium, an columbite. The name comes frae Greek meethology: Niobe, dauchter o Tantalus.