chemical element wi the atomic nummer o 27
(Reguidit frae Cobalt)

Cobaut is a chemical element wi symbol Co an atomic nummer 27. Lik nickel, cobaut in the Yird's crust is foond anly in chemically combined furm, save for smaa deposits foond in alloys o naitural meteoric iron. The free element, produced bi reductive smeltin, is a haird, lustrous, siller-gray metal.

Cobaut, 27Co
Template:Infobox element/symbol-to-top-image/alt
Appearancehaird lustrous gray metal
Standard atomic weight Ar, std(Co)58.933194(3)[2]
Cobaut 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


Atomic nummer (Z)27
Groupgroup 9
Periodperiod 4
Element category  Transeetion metal
Electron confeeguration[Ar] 3d7 4s2
Electrons per shell2, 8, 15, 2
Pheesical properties
Colourmetallic gray
Phase at STPsolit
Meltin pynt1768 K ​(1495 °C, ​2723 °F)
Bylin pynt3200 K ​(2927 °C, ​5301 °F)
Density (near r.t.)8.90 g/cm3
when liquid (at m.p.)7.75 g/cm3
Heat o fusion16.06 kJ/mol
Heat o vapourisation377 kJ/mol
Molar heat capacity24.81 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1790 1960 2165 2423 2755 3198
Atomic properties
Oxidation states−3, −1, 0, +1, +2, +3, +4, +5[3] (an amphoteric oxide)
ElectronegativityPauling scale: 1.88
Ionisation energies
Atomic radiusempirical: 125 pm
Covalent radius126±3 (law spin), 150±7 (heich spin) pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o cobaut
Ither properties
Naitural occurrenceprimordial
Creestal structurhexagonal close-packed (hcp)
Hexagonal close packed creestal structur for cobaut
Speed o soond thin rod4720 m/s (at 20 °C)
Thermal expansion13.0 µm/(m·K) (at 25 °C)
Thermal conductivity100 W/(m·K)
Electrical resistivity62.4 n Ω·m (at 20 °C)
Magnetic orderinferromagnetic
Young's modulus209 GPa
Shear modulus75 GPa
Bulk modulus180 GPa
Poisson ratio0.31
Mohs haurdness5.0
Vickers haurdness1043 MPa
Brinell haurdness700 MPa
CAS Nummer7440-48-4
DiskiveryGeorg Brandt (1732)
Main isotopes o cobaut
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
56Co syn 77.27 d ε 56Fe
57Co syn 271.79 d ε 57Fe
58Co syn 70.86 d ε 58Fe
59Co 100% stable
60Co syn 5.2714 y β, γ 60Ni
| references

Cobaut-based blue pigments (cobalt blue) hae been uised syne auncient times for jewelry an pents, an tae impairt a distinctive blue tint tae gless, but the colour wis later thocht bi alchemists tae be due tae the kent metal bismuth. Miners haed lang uised the name kobold ure (German for goblin ure) for some o the blue-pigment producin minerals; thay war sae named acause thay war puir in kent metals, an gae pushionous arsenic-containin fumes whan smeltit. In 1735, sic ures war foond tae be reducible tae a new metal (the first diskivert syne ancient times), an this wis ultimately named for the kobold.

The day, some cobaut is produced speceefically frae ane o a nummer o metallic-lustered ures, sic as for example cobaltite (CoAsS). The element is houiver mair uisually produced as a bi-product o capper an nickel minin. The capper belt in the Democratic Republic o the Congo (DRC) an Zambie yields maist o the global cobalt production. The DRC alane accountit for mair nor 50% o warld production in 2016 (123,000 tonnes), accordin tae Natural Resources Canada.[4]

Cobalt is primarily uised in the manufactur o magnetic, wear-resistant an heich-strenth alloys. The compoonds cobaut silicate an cobaut(II) aluminate (CoAl2O4, cobaut blue) gie a distinctive deep blue colour tae gless, ceramics, inks, pents an varnishes. Cobaut occurs naiturally as anerly ane stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, uised as a radioactive tracer an for the production o heich energy gamma rays.

Cobalt is the active centre o a group of coenzymes cried cobalamins. veetamin B12, the best-kent example of the teep, is an essential veetamin for aw ainimals. Cobaut in inorganic form is an aw a micronutrient for bacteria, algae, an fungi.


  1. Oxford English Dictionary, 2nd Edition 1989.
  2. 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.
  3. a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. pp. 1117–1119. ISBN 0080379419.
  4. Danielle Bochove (1 November 2017). "Electric car future spurs Cobalt rush: Swelling demand for product breathes new life into small Ontario town". Vancouver Sun. Bloomberg.