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 General | States | Energies | Oxidation & Electrons | Appearance & Characteristics | Reactions | Other Forms Radius | Conductivity | Abundance


Name: Cobalt Symbol: Co
Group: Trans. Met. Atomic weight: 58.9332
Density @ 293 K: 8.90 g/cm3 Atomic volume: 6.7 cm3/mol
Group: Trans. Met. discovered: 1737


state (s, l, g): s
melting point: 1768.2 K boiling point: 3373 K
Heat of fusion: 16.190 kJ/mol Heat of vaporization: 376.50 kJ/mol


1st ionization energy: 758.4 kJ/mole
electronegativity: 1.88 2nd ionization energy: 1646 kJ/mole
electron affinity: 63.8 kJ/mole 3rd ionization energy: 3232.2 kJ/mole
Specific heat: 0.42 J/gK heat atomization: 425 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,15,2 electron configuration: [Ar] 3d7 4s2
minimum oxidation number: -1 maximum oxidation number: 5
min. common oxidation no.: 0 max. common oxidation no.: 3

Appearance & Characteristics:

structure: hcp: hexagonal close pkd color: bluish-white
uses: magnets, Co glass (blue) toxicity:
hardness: mohs characteristics: hard


reaction with air: mild, w/ht =>Co3O4
reaction with 6M HCl: mild, =>H2, CoCl2 reaction with 6M HCl: mild, =>H2, CoCl2
reaction with 15M HNO3: vigorous, =>Co(NO3)2, NOx reaction with 6M NaOH:

Other Forms:

number of isotopes: 1 hydride(s): none
oxide(s): CoO Co3O4 chloride(s): CoCl2


ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 125 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): 83.8 pm ionic radius (3+ ion): 71.8 pm


thermal conductivity: 100 J/m-sec-deg
electrical conductivity: 160.256 1/mohm-cm polarizability: 7.5 A^3


source: Co sulfides & arsenides
rel. abund. solar system: 3.352 log abundance earth's crust: 1.4 log
cost, pure: 21 $/100g cost, bulk: $/100g