![Template:Infobox element/symbol-to-top-image/alt](//upload.wikimedia.org/wikipedia/commons/thumb/a/a8/Kobalt_electrolytic_and_1cm3_cube.jpg/220px-Kobalt_electrolytic_and_1cm3_cube.jpg) |
Cobaut |
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Pronunciation | i[1] |
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Appearance | haird lustrous gray metal |
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Standard atomic weight Ar, std(Co) | 7001589331940000000♠58.933194(3)[2] |
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Cobaut in the periodic cairt |
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- ↑ Co ↓ Rh |
iron ← cobaut → nickel |
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Atomic nummer (Z) | 27 |
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Group | group 9 |
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Period | period 4 |
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Block | d-block |
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Element category | Transeetion metal |
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Electron confeeguration | [Ar] 3d7 4s2 |
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Electrons per shell | 2, 8, 15, 2 |
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Pheesical properties |
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Colour | metallic gray |
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Phase at STP | solit |
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Meltin pynt | 1768 K (1495 °C, 2723 °F) |
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Bylin pynt | 3200 K (2927 °C, 5301 °F) |
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Density (near r.t.) | 8.90 g/cm3 |
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when liquid (at m.p.) | 7.75 g/cm3 |
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Heat o fusion | 16.06 kJ/mol |
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Heat o vapourisation | 377 kJ/mol |
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Molar heat capacity | 24.81 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
1790 |
1960 |
2165 |
2423 |
2755 |
3198 |
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Atomic properties |
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Oxidation states | −3, −1, 0, +1, +2, +3, +4, +5[3] (an amphoteric oxide) |
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Electronegativity | Pauling scale: 1.88 |
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Ionisation energies | |
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Atomic radius | empirical: 125 pm |
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Covalent radius | 126±3 (law spin), 150±7 (heich spin) pm |
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Colour lines in a spectral rangeSpectral lines o cobaut |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | hexagonal close-packed (hcp) |
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Speed o soond thin rod | 4720 m/s (at 20 °C) |
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Thermal expansion | 13.0 µm/(m·K) (at 25 °C) |
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Thermal conductivity | 100 W/(m·K) |
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Electrical resistivity | 62.4 n Ω·m (at 20 °C) |
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Magnetic orderin | ferromagnetic |
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Young's modulus | 209 GPa |
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Shear modulus | 75 GPa |
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Bulk modulus | 180 GPa |
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Poisson ratio | 0.31 |
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Mohs haurdness | 5.0 |
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Vickers haurdness | 1043 MPa |
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Brinell haurdness | 700 MPa |
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CAS Nummer | 7440-48-4 |
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History |
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Diskivery | Georg Brandt (1732) |
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Main isotopes o cobaut |
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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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| references |