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.

  1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
Niobium, 41Nb
Template:Infobox element/symbol-to-top-image/alt
Niobium
Pronunciation/nˈbiəm/ (ny-OH-bee-əm)
Appearancegray metallic, bluish when oxidized
Standard atomic weight Ar, std(Nb)92.90637(1)[1]
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 Gowd 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
zirconiumniobiummolybdenum
Atomic nummer (Z)41
Groupgroup 5
Periodperiod 5
Blockd-block
Element category  Transeetion metal
Electron confeeguration[Kr] 4d4 5s1
Electrons per shell2, 8, 18, 12, 1
Pheesical properties
Phase at STPsolid
Meltin pynt2750 K ​(2477 °C, ​4491 °F)
Bylin pynt5017 K ​(4744 °C, ​8571 °F)
Density (near r.t.)8.57 g/cm3
Heat o fusion30 kJ/mol
Heat o vapourisation689.9 kJ/mol
Molar heat capacity24.60 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−3, −1, +1, +2, +3, +4, +5 (a mildly acidic oxide)
ElectronegativityPauling scale: 1.6
Ionisation energies
  • 1st: 652.1 kJ/mol
  • 2nd: 1380 kJ/mol
  • 3rd: 2416 kJ/mol
Atomic radiusempirical: 146 pm
Covalent radius164±6 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o niobium
Ither properties
Naitural occurrenceprimordial
Creestal structur ​cubic bouk-centred
[[File:cubic bouk-centred|frameless|alt=Cubic bouk-centred creestal structur for niobium|upright=0.23|Cubic bouk-centred creestal structur for niobium]]
Speed o soond thin rod3480 m/s (at 20 °C)
Thermal expansion7.3 µm/(m·K)
Thermal conductivity53.7 W/(m·K)
Electrical resistivity152 nΩ·m (at 0 °C)
Magnetic orderinparamagnetic
Young's modulus105 GPa
Shear modulus38 GPa
Bulk modulus170 GPa
Poisson ratio0.40
Mohs haurdness6.0
Vickers haurdness870–1320 MPa
Brinell haurdness735–2450 MPa
CAS Nummer7440-03-1
History
Naminafter Niobe in Greek meethologie, dochter o Tantalus (tantalum)
DiskiveryCharles Hatchett (1801)
First isolationChristian Wilhelm Blomstrand (1864)
Recognised as a distinct element biHeinrich Rose (1844)
Main isotopes o niobium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
90Nb syn 15 h β+ 90Zr
91Nb syn 680 y ε 91Zr
91mNb syn 61 d IT 91Nb
92m1Nb syn 10 d ε 92Zr
γ
92Nb trace 3.47×107 y ε 92Zr
γ
93Nb 100% stable
93mNb syn 16 y IT 93Nb
94Nb trace 20.3×103 y β 94Mo
γ
95Nb syn 35 d β 95Mo
γ
95mNb syn 4 d IT 95Nb
96Nb syn 24 h β 96Mo
| references