Niobium

Niobium,  ₄₁Nb

General properties
Appearance	gray metallic, bluish whan oxidised
Staundart atomic wecht (Ar, staundart)	7001929063700000000♠92.90637(2)
Niobium in the periodic cairt
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium V ↑ Nb ↓ Ta zirconium ← niobium → molybdenum
Atomic nummer (Z)	41
Group	group 5
Period	period 5
Block	d-block
Electron confeeguration	[Kr] 4d4 5s1
Electrons per shell	2, 8, 18, 12, 1
Pheesical properties
Phase (at STP)	solit
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
Spectral lines
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)
Main isotopes o niobium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 91Nb syn 6.8×102 y ε 91Zr 91mNb syn 60.86 d IT 91Nb 92Nb syn 10.15 d ε 92Zr γ - 92Nb syn 3.47×107y ε 92Zr γ - 93Nb 100% - (SF) 93mNb syn 16.13 y IT 93Nb 94Nb syn 2.03×104 y β− 94Mo γ - 95Nb syn 34.991 d β− 95Mo γ - 95mNb syn 3.61 d IT 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.