Kobalto

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Cobalt
27Co
-

Co

Rh
ironcobaltnickel
Appearance
hard lustrous gray metal
General properties
Name, simbolo, kaiphan cobalt, Co, 27
Pronunciation Plantilya:IPAc-en Plantilya:Respell[1]
Element category puthaw nga transisyon
Group, period, block 94, d
Standard atomic weight 58.933195(5)
Electron configuration [Ar] 4s2 3d7
2, 8, 15, 2
Electron shells of cobalt (2, 8, 15, 2)
History
Discovery Georg Brandt (1732)
Physical properties
Color metallic gray
Phase magahi
Density (near r.t.) 8.90 g·cm−3
Liquid density at m.p. 7.75 g·cm−3
Melting point 1768 K, 1495 °C, 2723 °F
Boiling point 3200 K, 2927 °C, 5301 °F
Heat of fusion 16.06 kJ·mol−1
Heat of vaporization 377 kJ·mol−1
Molar heat capacity 24.81 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1790 1960 2165 2423 2755 3198
Atomic properties
Oxidation states 5, 4, 3, 2, 1, -1[2]
(amphoteric oxide)
Electronegativity 1.88 (Pauling scale)
Ionization energies
(more)
1st: 760.4 kJ·mol−1
2nd: 1648 kJ·mol−1
3rd: 3232 kJ·mol−1
Atomic radius 125 pm
Covalent radius 126±3 (low spin), 150±7 (high spin) pm
Miscellanea
Crystal structure hexagonal
Cobalt has a hexagonal crystal structure
Magnetic ordering ferromagnetic
Electrical resistivity (20 °C) 62.4 nΩ·m
Thermal conductivity 100 W·m−1·K−1
Thermal expansion (25 °C) 13.0 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 4720 m·s−1
Young's modulus 209 GPa
Shear modulus 75 GPa
Bulk modulus 180 GPa
Poisson ratio 0.31
Mohs hardness 5.0
Vickers hardness 1043 MPa
Brinell hardness 700 MPa
CAS registry number 7440-48-4
Most stable isotopes
Main article: Isotopes of cobalt
iso NA half-life DM DE (MeV) DP
56Co syn 77.27 d ε 4.566 56Fe
57Co syn 271.79 d ε 0.836 57Fe
58Co syn 70.86 d ε 2.307 58Fe
59Co 100% 59Co is stable with 32 neutrons
60Co syn 5.2714 years β, γ 2.824 60Ni
t  h  u
· r

Ang kobalto (Iningles cobalt) mao ang elementong kimiko sa talaang peryodiko nga may simbolo nga Co ug kaiphan nga atomik 27. Ang kobalto mao ang puthaw nga transisyon.

Ang mga gi basihan niini[usba | edit source]

  1. Oxford English Dictionary, 2nd Edition 1989.
  2. Plantilya:Greenwood&Earnshaw2nd


Galeriya sa hulagway[usba | edit source]