Cobalt (Co)

Light grey transition element. Some meteorites contain small amounts of metallic cobalt. Generally alloyed for use. Mammals require small amounts of cobalt salts. Cobalt-60, an artificially produced radioactive isotope of Cobalt is an important radioactive tracer and cancer-treatment agent. Discovered by G. Brandt in 1737.

Atomic Number	27
Atomic Weight	58.933194
Mass Number	59

Group	9
Period	4
Block	d

Protons	27 p⁺
Neutrons	32 n⁰
Electrons	27 e^-

Properties

Energy
Atomic Radius	135 pm 233 pm
Molar Volume	6.7 cm³/mol
Covalent Radius	111 pm 103 pm 96 pm 137 pm 138 pm
Metallic Radius	116 pm 125 pm
Ionic Radius	58 pm 67 pm 65 pm 74.5 pm 90 pm 54.5 pm 61 pm 40 pm 53 pm
Crystal Radius	72 pm 81 pm 79 pm 88.5 pm 104 pm 68.5 pm 75 pm 54 pm 67 pm
Van der Waals Radius	200 pm 200 pm 223 pm 287.2 pm
Density	8.86 g/cm³ 7,750 kg/m³
Proton Affinity	742.7 kJ/mol
Electron Affinity	0.66225646 eV/particle
Ionization Energy	7.88101 eV/particle 17.0844 eV/particle 33.5 eV/particle 51.27 eV/particle 79.5 eV/particle 102 eV/particle 129 eV/particle 157.8 eV/particle 186.14 eV/particle 275.4 eV/particle 305.32 eV/particle 336.15 eV/particle 378.55 eV/particle 410 eV/particle 441.1 eV/particle 511.96 eV/particle 546.588 eV/particle 1,397.2 eV/particle 1,504.5 eV/particle 1,606 eV/particle 1,724 eV/particle 1,844 eV/particle 1,960.83 eV/particle 2,119.4 eV/particle 2,218.876 eV/particle 9,544.183 eV/particle 10,012.122 eV/particle

Heat of Vaporization	389.1 kJ/mol
Heat of Fusion	15.48 kJ/mol
Heat of Formation	426.7 kJ/mol
Electrons
Electron Shells	2, 8, 15, 2

Valence Electrons	2
Electron Configuration	[Ar] 3d⁷ 4s²

Oxidation States	-3, -1, 0, 1, 2, 3, 4, 5
Electronegativity	10.86 eV/particle 0.1432363 1.88
Electrophilicity	1.2638504937543713 eV/particle
Phases
Phase	Solid
Gas Phase
Boiling Point	3,200.15 K
Melting Point	1,768.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color	Gray #ff1493 #f090a0 #f090a0
Appearance	hard lustrous gray metal
Refractive Index
Thermodynamic Properties
Thermal Conductivity	100 W/(m K)
Thermal Expansion	0.000013 1/K
Molar Heat Capacity	24.81 J/(mol K)
Specific Heat Capacity	0.421 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	17 MS/m
Electrical Resistivity	0.00000006000000000002 m Ω
Superconducting Point
Magnetism
Type	ferromagnetic
Magnetic Susceptibility (Mass)
Magnetic Susceptibility (Molar)
Magnetic Susceptibility (Volume)
Magnetic Ordering
Curie Point	1,394 K
Neel Point
Structure
Crystal Structure	Simple Hexagonal (HEX)
Lattice Constant	2.51 Å
Lattice Angles	π/2, π/2, 2 π/3
Mechanical Properties
Hardness	700 MPa 5 MPa 1,043 MPa
Bulk Modulus	180 GPa
Shear Modulus	75 GPa
Young Modulus	209 GPa
Poisson Ratio	0.31
Speed of Sound	4,720 m/s
Classification
Category	Transition metals, Transition metals
CAS Group	VIIIA
IUPAC Group	VIII
Glawe Number	70
Mendeleev Number	63
Pettifor Number	64
Geochemical Class	first series transition metal
Goldschmidt Class	siderophile
Other
Gas Basicity	719.8 kJ/mol
Dipole Polarizability	55 ± 4 a₀
C6 Dispersion Coefficient	408 a₀ 461 a₀
Allotropes
Neutron Cross Section	37.2
Neutron Mass Absorption	0.021
Quantum Numbers	4F9/2
Space Group	194 (P63/mmc)

Isotopes of Cobalt

Stable Isotopes	1
Unstable Isotopes	31
Radioactive Isotopes	28

⁴⁷Co

Abundance
Relative Atomic Mass	47.011401 ± 0.000644 Da
Mass Number	47
G-Factor
Half Life
Spin	7/2
Quadrupole Moment
Discovery Year
Parity	-

⁴⁷Co Decay Modes

Decay Mode	Intensity
p (proton emission)	%

⁴⁸Co

Abundance
Relative Atomic Mass	48.001857 ± 0.000537 Da
Mass Number	48
G-Factor
Half Life
Spin	6
Quadrupole Moment
Discovery Year
Parity	+

⁴⁸Co Decay Modes

Decay Mode	Intensity
p (proton emission)	%

⁴⁹Co

Abundance
Relative Atomic Mass	48.989501 ± 0.000537 Da
Mass Number	49
G-Factor
Half Life
Spin	7/2
Quadrupole Moment
Discovery Year
Parity	-

⁴⁹Co Decay Modes

Decay Mode	Intensity
p (proton emission)	%

⁵⁰Co

Abundance	Radioactive ☢️
Relative Atomic Mass	49.981117 ± 0.000135 Da
Mass Number	50
G-Factor
Half Life	38.8 ± 0.2 ms
Spin	6
Quadrupole Moment
Discovery Year	1987
Parity	+

⁵⁰Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	70.5%
2p (2-proton emission)	%

⁵¹Co

Abundance	Radioactive ☢️
Relative Atomic Mass	50.970647 ± 0.000052 Da
Mass Number	51
G-Factor
Half Life	68.8 ± 1.9 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1987
Parity	-

⁵¹Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	3.8%

⁵²Co

Abundance	Radioactive ☢️
Relative Atomic Mass	51.963130224 ± 0.000005669 Da
Mass Number	52
G-Factor
Half Life	111.7 ± 2.1 ms
Spin	6
Quadrupole Moment
Discovery Year	1987
Parity	+

⁵²Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	%

⁵³Co

Abundance	Radioactive ☢️
Relative Atomic Mass	52.954203278 ± 0.000001854 Da
Mass Number	53
G-Factor
Half Life	244.6 ± 2.8 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1970
Parity	-

⁵³Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁵⁴Co

Abundance	Radioactive ☢️
Relative Atomic Mass	53.948459075 ± 0.00000038 Da
Mass Number	54
G-Factor	0
Half Life	193.27 ± 0.06 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1952
Parity	+

⁵⁴Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁵⁵Co

Abundance	Radioactive ☢️
Relative Atomic Mass	54.941996416 ± 0.000000434 Da
Mass Number	55
G-Factor	1.3777142857143 ± 0.00085714285714286
Half Life	17.53 ± 0.03 h
Spin	7/2
Quadrupole Moment
Discovery Year	1938
Parity	-

⁵⁵Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁵⁶Co

Abundance	Radioactive ☢️
Relative Atomic Mass	55.939838032 ± 0.00000051 Da
Mass Number	56
G-Factor	0.9625 ± 0.0025
Half Life	77.236 ± 0.026 d
Spin	4
Quadrupole Moment	0.25 ± 0.09
Discovery Year	1941
Parity	+

⁵⁶Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

⁵⁷Co

Abundance	Radioactive ☢️
Relative Atomic Mass	56.936289819 ± 0.000000553 Da
Mass Number	57
G-Factor	1.3485714285714 ± 0.0028571428571429
Half Life	271.811 ± 0.032 d
Spin	7/2
Quadrupole Moment	0.54 ± 0.1
Discovery Year	1941
Parity	-

⁵⁷Co Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	100%

⁵⁸Co

Abundance	Radioactive ☢️
Relative Atomic Mass	57.935751292 ± 0.000001237 Da
Mass Number	58
G-Factor	2.022 ± 0.004
Half Life	70.844 ± 0.02 d
Spin	2
Quadrupole Moment	0.23 ± 0.03
Discovery Year	1941
Parity	+

⁵⁸Co Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
e⁺ (positron emission)	14.79%
ϵ (electron capture)	85.21%

⁵⁹Co

Abundance	100
Relative Atomic Mass	58.933193524 ± 0.000000426 Da
Mass Number	59
G-Factor
Half Life
Spin	7/2
Quadrupole Moment	0.42 ± 0.03
Discovery Year	1923
Parity	-

⁶⁰Co

Abundance	Radioactive ☢️
Relative Atomic Mass	59.933815536 ± 0.000000433 Da
Mass Number	60
G-Factor	0.7598 ± 0.0016
Half Life	5.2714 ± 0.0006 y
Spin	5
Quadrupole Moment	0.46 ± 0.06
Discovery Year	1941
Parity	+

⁶⁰Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶¹Co

Abundance	Radioactive ☢️
Relative Atomic Mass	60.932476031 ± 0.000000901 Da
Mass Number	61
G-Factor
Half Life	1.649 ± 0.005 h
Spin	7/2
Quadrupole Moment
Discovery Year	1947
Parity	-

⁶¹Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶²Co

Abundance	Radioactive ☢️
Relative Atomic Mass	61.934058198 ± 0.00001994 Da
Mass Number	62
G-Factor
Half Life	1.54 ± 0.1 m
Spin	2
Quadrupole Moment
Discovery Year	1949
Parity

⁶²Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶³Co

Abundance	Radioactive ☢️
Relative Atomic Mass	62.93359963 ± 0.000019941 Da
Mass Number	63
G-Factor
Half Life	26.9 ± 0.4 s
Spin	7/2
Quadrupole Moment
Discovery Year	1960
Parity	-

⁶³Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶⁴Co

Abundance	Radioactive ☢️
Relative Atomic Mass	63.935810176 ± 0.000021476 Da
Mass Number	64
G-Factor
Half Life	300 ± 30 ms
Spin	1
Quadrupole Moment
Discovery Year	1969
Parity	+

⁶⁴Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶⁵Co

Abundance	Radioactive ☢️
Relative Atomic Mass	64.936462071 ± 0.000002235 Da
Mass Number	65
G-Factor
Half Life	1.16 ± 0.03 s
Spin	7/2
Quadrupole Moment
Discovery Year	1978
Parity

⁶⁵Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

⁶⁶Co

Abundance	Radioactive ☢️
Relative Atomic Mass	65.939442943 ± 0.000015 Da
Mass Number	66
G-Factor
Half Life	194 ± 17 ms
Spin	1
Quadrupole Moment
Discovery Year	1985
Parity	+

⁶⁶Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%

⁶⁷Co

Abundance	Radioactive ☢️
Relative Atomic Mass	66.940609625 ± 0.000006917 Da
Mass Number	67
G-Factor
Half Life	329 ± 28 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1985
Parity	-

⁶⁷Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%

⁶⁸Co

Abundance	Radioactive ☢️
Relative Atomic Mass	67.944559401 ± 0.000004142 Da
Mass Number	68
G-Factor
Half Life	200 ± 20 ms
Spin	7
Quadrupole Moment
Discovery Year	1985
Parity	-

⁶⁸Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%

⁶⁹Co

Abundance	Radioactive ☢️
Relative Atomic Mass	68.945909 ± 0.000092 Da
Mass Number	69
G-Factor
Half Life	180 ± 20 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1985
Parity	-

⁶⁹Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%

⁷⁰Co

Abundance	Radioactive ☢️
Relative Atomic Mass	69.9500534 ± 0.0000118 Da
Mass Number	70
G-Factor
Half Life	508 ± 7 ms
Spin	1
Quadrupole Moment
Discovery Year	1998
Parity	+

⁷⁰Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

⁷¹Co

Abundance	Radioactive ☢️
Relative Atomic Mass	70.952366923 ± 0.00049923 Da
Mass Number	71
G-Factor
Half Life	80 ± 3 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1992
Parity	-

⁷¹Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	3%

⁷²Co

Abundance	Radioactive ☢️
Relative Atomic Mass	71.956736 ± 0.000322 Da
Mass Number	72
G-Factor
Half Life	51.5 ± 0.3 ms
Spin	6
Quadrupole Moment
Discovery Year	1992
Parity	-

⁷²Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	4%
2n (2-neutron emission)	%

⁷³Co

Abundance	Radioactive ☢️
Relative Atomic Mass	72.959238 ± 0.000322 Da
Mass Number	73
G-Factor
Half Life	42 ± 0.8 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1995
Parity	-

⁷³Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	6%
2n (2-neutron emission)	%

⁷⁴Co

Abundance	Radioactive ☢️
Relative Atomic Mass	73.963993 ± 0.000429 Da
Mass Number	74
G-Factor
Half Life	31.3 ± 1.3 ms
Spin	7
Quadrupole Moment
Discovery Year	1995
Parity	-

⁷⁴Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	18%
2n (2-neutron emission)	%

⁷⁵Co

Abundance	Radioactive ☢️
Relative Atomic Mass	74.967192 ± 0.000429 Da
Mass Number	75
G-Factor
Half Life	26.5 ± 1.2 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1995
Parity	-

⁷⁵Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	16%
2n (2-neutron emission)	%

⁷⁶Co

Abundance	Radioactive ☢️
Relative Atomic Mass	75.972453 ± 0.000537 Da
Mass Number	76
G-Factor
Half Life	23 ± 6 ms
Spin	8
Quadrupole Moment
Discovery Year	2010
Parity	-

⁷⁶Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

⁷⁷Co

Abundance	Radioactive ☢️
Relative Atomic Mass	76.976479 ± 0.000644 Da
Mass Number	77
G-Factor
Half Life	15 ± 6 ms
Spin	7/2
Quadrupole Moment
Discovery Year	2014
Parity	-

⁷⁷Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%
3n (3-neutron emission)	%

⁷⁸Co

Abundance	Radioactive ☢️
Relative Atomic Mass	77.983553 ± 0.000751 Da
Mass Number	78
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year	2017
Parity

⁷⁸Co Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

History

Cobalt compounds have been used for centuries to impart a rich blue color to glass, glazes and ceramics. The element was first isolated by Swedish chemist George Brandt in 1735. He showed it was the presence of the element cobalt that caused the blue color in glass, not bismuth as previously thought. From the German word Kobald, goblin or evil spirit; also from the Greek cobalos, mine

Discoverers	George Brandt
Discovery Location	Sweden
Discovery Year	1739
Etymology (Name Origin)	German: kobold (goblin).
Pronunciation	KO-bolt (English)

Cobalt and its compounds are considered to be slightly toxic

Supplemental colbalt is essential in sheep's diets to improve the wools quality

Uses

Cobalt is used in the preparation of magnetic, wear-resistant and high-strength alloys. Cobalt is widely used in batteries and in electroplating. Radioactive ⁶⁰Co is used in the treatment of cancer. A solution of the chloride is used as a sympathetic ink. Used in many hard alloys; for magnets, ceramics and special glasses. Remains hard up to 982°C. Radioactive cobalt-60 is used in cancer therapy.

Sources

Occurs in compounds with arsenic, oxygen and sulfur as in cobaltine (CoAsS) and linneite (Co3S4). Pure cobalt is obtained as a byproduct of refining nickel, copper and iron.

Abundance
Abundance in Earth's crust	25 mg/kg
Abundance in Oceans	0.00002 mg/L
Abundance in Human Body	0.000002 %
Abundance in Meteor	0.059 %
Abundance in Sun	0.0004 %
Abundance in Universe	0.0003 %

Nuclear Screening Constants

1	s	0.6332
2	p	3.9076
2	s	7.595
3	d	15.1446
3	p	13.5654
3	s	12.6777
4	s	21.4236

Cobalt on ChemicalAid

AGROVOC ID	c_1702
Art & Architecture Thesaurus ID	300221155
Australian Educational Vocabulary ID	scot/3511
BNCF Thesaurus ID	22939
Bibliothèque nationale de France ID	119794179
Brockhaus Enzyklopädie online ID	kobalt
CAB ID	105528
CA PROP 65 ID	cobalt-metal-powder
CAS Registry Number	7440-48-4
CPV Supplementary	AA16
Canadian Encyclopedia article ID	cobalt
ChEBI ID	27638
DSSTOX compound identifier	DTXCID9011040
DSSTox substance ID	DTXSID1031040
DrugBank ID	14574
ECHA Substance Infocard ID	100.028.325
Encyclopædia Britannica Online ID	science/cobalt-chemical-element
Encyclopædia Universalis ID	cobalt
EuroVoc ID	6018
Freebase ID	/m/025tkrf
French Vikidia ID	Cobalt
GEMET ID	1532
GND ID	4070047-1
Great Russian Encyclopedia Online ID	2075823
Grove Art Online ID	T2071458
HCIS ID	1033
HSDB ID	519
ICSC ID	0782
IEDB Epitope ID	114073
InChIKey	GUTLYIVDDKVIGB-UHFFFAOYSA-N
KBpedia ID	Cobalt
Latvian National Encyclopedia Online ID	112080
Library of Congress authority ID	sh85027513
MeSH descriptor ID	D003035
NALT ID	27388
NDF-RT ID	N0000022936
NKCR AUT ID	ph543047
National Diet Library ID	00566072
National Library of Israel J9U ID	987007284052205171
OmegaWiki Defined Meaning	645
OpenAlex ID	C515602321
PSH ID	5779
RxNorm ID	1310300
Spanish Cultural Heritage thesauri ID	materias/1010032
Spanish Vikidia ID	Cobalto
Store norske leksikon ID	kobolt
Treccani ID	cobalto
UK Parliament thesaurus ID	285732
UNII	3G0H8C9362
WikiSkripta ID	30617
WordNet 3.1 Synset ID	14659468-n
YSO ID	15221
Yle topic ID	18-14370
ZVG number	7270

Cobalt (Co)

Properties

Isotopes of Cobalt

47Co

47Co Decay Modes

48Co

48Co Decay Modes

49Co

49Co Decay Modes

50Co

50Co Decay Modes

51Co

51Co Decay Modes

52Co

52Co Decay Modes

53Co

53Co Decay Modes

54Co

54Co Decay Modes

55Co

55Co Decay Modes

56Co

56Co Decay Modes

57Co

57Co Decay Modes

58Co

58Co Decay Modes

59Co

60Co

60Co Decay Modes

61Co

61Co Decay Modes

62Co

62Co Decay Modes

63Co

63Co Decay Modes

64Co

64Co Decay Modes

65Co

65Co Decay Modes

66Co

66Co Decay Modes

67Co

67Co Decay Modes

68Co

68Co Decay Modes

69Co

69Co Decay Modes

70Co

70Co Decay Modes

71Co

71Co Decay Modes

72Co

72Co Decay Modes

73Co

73Co Decay Modes

74Co

74Co Decay Modes

75Co

75Co Decay Modes

76Co

76Co Decay Modes

77Co

77Co Decay Modes

78Co

78Co Decay Modes