Cobaut

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

Cobaut
Pronunciation	i/ˈkoʊbɒlt/[1]
Appearance	haird lustrous gray metal
Standard atomic weight Ar, std(Co)	7001589331940000000♠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 - ↑ Co ↓ Rh iron ← cobaut → nickel
Atomic nummer (Z)	27
Group	group 9
Period	period 4
Block	d-block
Element category	Transeetion metal
Electron confeeguration	[Ar] 3d7 4s2
Electrons per shell	2, 8, 15, 2
Pheesical properties
Colour	metallic gray
Phase at STP	solit
Meltin pynt	1768 K ​(1495 °C, ​2723 °F)
Bylin pynt	3200 K ​(2927 °C, ​5301 °F)
Density (near r.t.)	8.90 g/cm3
when liquid (at m.p.)	7.75 g/cm3
Heat o fusion	16.06 kJ/mol
Heat o vapourisation	377 kJ/mol
Molar heat capacity	24.81 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)
Electronegativity	Pauling scale: 1.88
Ionisation energies	(more)
Atomic radius	empirical: 125 pm
Covalent radius	126±3 (law spin), 150±7 (heich spin) pm
Spectral lines o cobaut
Ither properties
Naitural occurrence	primordial
Creestal structur	​hexagonal close-packed (hcp)
Speed o soond thin rod	4720 m/s (at 20 °C)
Thermal expansion	13.0 µm/(m·K) (at 25 °C)
Thermal conductivity	100 W/(m·K)
Electrical resistivity	62.4 n Ω·m (at 20 °C)
Magnetic orderin	ferromagnetic
Young's modulus	209 GPa
Shear modulus	75 GPa
Bulk modulus	180 GPa
Poisson ratio	0.31
Mohs haurdness	5.0
Vickers haurdness	1043 MPa
Brinell haurdness	700 MPa
CAS Nummer	7440-48-4
History
Diskivery	Georg 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
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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.