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Co Cobalt
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

27
Co
Cobalt
Element 27 of Periodic table is Cobalt with atomic number 27, atomic weight 58.9332. Cobalt, symbol Co, has a Simple Hexagonal structure and Gray color. Cobalt is a Transition Metal element. It is part of group 9 (cobalt family). Know everything about Cobalt Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
27 Co - Cobalt | SchoolMyKids

Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

It belongs to group 9 of the periodic table having trivial name .

Cobalt Facts

Read key information and facts about element Cobalt

NameCobalt
Atomic Number27
Atomic SymbolCo
Atomic Weight58.9332
PhaseSolid
ColorGray
Appearancehard lustrous gray metal
ClassificationTransition Metal
Group in Periodic Table9
Group Namecobalt family
Period in Periodic Tableperiod 4
Block in Periodic Tabled -block
Electronic Configuration[Ar] 3d7 4s2
Electronic Shell Structure (Electrons per shell)2, 8, 15, 2
Melting Point1768 K
Boiling Point3200 K
CAS NumberCAS7440-48-4
Neighborhood Elements
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Cobalt on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 27 to find Cobalt on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Cobalt on periodic table look for cross section of group 9 and period 4 in the modern periodic table.

Cobalt History

The element Cobalt was discovered by G. Brandt in year 1735 in Sweden. Cobalt was first isolated by G. Brandt in 1735. Cobalt derived its name from the German word Kobold, meaning 'goblin'.

Proved that the blue color of glass is due to a new kind of metal and not bismuth as thought previously.

Cobalt Presence: Abundance in Nature and Around Us

The table below shows the abundance of Cobalt in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe300060
Abundance in Sun400070
Abundance in Meteorites600000200000
Abundance in Earth's Crust3000010000
Abundance in Oceans0.080.008
Abundance in Humans202

Crystal Structure of Cobalt

The solid state structure of Cobalt is Simple Hexagonal.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
250.71 pm250.71 pm406.95 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 2 π/3

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameP63/mmc 27 Co Cobalt - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number194
Crystal StructureSimple Hexagonal

Cobalt Atomic and Orbital Properties

Cobalt atoms have 27 electrons and the electronic shell structure is [2, 8, 15, 2] with Atomic Term Symbol (Quantum Numbers) 4F9/2.

Atomic Number27
Number of Electrons (with no charge)27
Number of Protons27
Mass Number59
Number of Neutrons32
Shell structure (Electrons per energy level)2, 8, 15, 2
Electron Configuration[Ar] 3d7 4s2
Valence Electrons3d7 4s2
Valence (Valency)4
Main Oxidation States2, 3
Oxidation States-3, -1, 0, 1, 2, 3, 4, 5
Atomic Term Symbol (Quantum Numbers)4F9/2

Bohr Atomic Model of Cobalt - Electrons per energy level

27 Co Cobalt - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Cobalt - neutral Cobalt atom

Abbreviated electronic configuration of Cobalt

The ground state abbreviated electronic configuration of Neutral Cobalt atom is [Ar] 3d7 4s2. The portion of Cobalt configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 3d7 4s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Cobalt

Complete ground state electronic configuration for the Cobalt atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d7 4s2

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Cobalt
    Atomic Structure of Cobalt

    Cobalt atomic radius is 152 pm, while it's covalent radius is 126 pm.

    Atomic Radius Calculated

    152 pm (1.52 Å)

    Atomic Radius Empirical

    135 pm (1.35 Å)

    Atomic Volume6.62 cm3/mol
    Covalent Radius126 pm (1.26 Å)
    Van der Waals Radius-
    Neutron Cross Section37.2
    Neutron Mass Absorption 0.021

    Atomic Spectrum of Cobalt

    Atomic Spectrum of Cobalt | SchoolMyKids

    Cobalt Chemical Properties: Cobalt Ionization Energies and electron affinity

    The electron affinity of Cobalt is 63.7 kJ/mol.

    Valence4
    Electronegativity1.88
    ElectronAffinity63.7 kJ/mol

    Ionization Energy of Cobalt

    Refer to table below for Ionization energies of Cobalt

    Ionization energy numberEnthalpy - kJ/mol
    1st760.4
    2nd1648
    3rd3232
    4th4950
    5th7670
    6th9840
    7th12440
    8th15230
    9th17959
    10th26570
    11th29400
    12th32400
    13th36600
    14th39700
    15th42800
    16th49396
    17th52737
    18th134810
    19th145170
    20th154700
    21st167400
    22nd178100
    23rd189300
    24th204500
    25th214100
    26th920870
    27th966023

    Cobalt Physical Properties

    Refer to below table for Cobalt Physical Properties

    Density8.9 g/cm3(when liquid at m.p density is $7.75 g/cm3)
    Molar Volume6.62 cm3/mol

    Elastic Properties

    Young Modulus209
    Shear Modulus75 GPa
    Bulk Modulus 180 GPa
    Poisson Ratio0.31

    Hardness of Cobalt - Tests to Measure of Hardness of Element

    Mohs Hardness5 MPa
    Vickers Hardness1043 MPa
    Brinell Hardness700 MPa

    Cobalt Electrical Properties

    Cobalt is Conductor of electricity. Refer to table below for the Electrical properties ofCobalt

    Electrical Conductivity17000000 S/m
    Resistivity6e-8 m Ω
    Superconducting Point-

    Cobalt Heat and Conduction Properties

    Thermal Conductivity100 W/(m K)
    Thermal Expansion0.000013 /K

    Cobalt Magnetic Properties

    Magnetic TypeFerromagnetic
    Curie Point1394 K
    Mass Magnetic Susceptibility-
    Molar Magnetic Susceptibility-
    Volume Magnetic Susceptibility-

    Optical Properties of Cobalt

    Refractive Index-

    Acoustic Properties of Cobalt

    Speed of Sound4720 m/s

    Cobalt Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Cobalt

    Melting Point1768 K (1494.85°C, 2722.73 °F)
    Boiling Point3200 K (2926.85°C, 5300.33 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Cobalt

    Heat of Fusion16.2 kJ/mol
    Heat of Vaporization375 kJ/mol
    Heat of Combustion-

    Cobalt Isotopes - Nuclear Properties of Cobalt

    Cobalt has 29 isotopes, with between 47 and 75 nucleons. Cobalt has 1 stable naturally occuring isotopes.

    Isotopes of Cobalt - Naturally occurring stable Isotopes: 59Co.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    47Co272047Synthetic
    48Co272148Synthetic
    49Co272249Synthetic
    50Co272350Synthetic
    51Co272451Synthetic
    52Co272552Synthetic
    53Co272653Synthetic
    54Co272754Synthetic
    55Co272855Synthetic
    56Co272956Synthetic
    57Co273057Synthetic
    58Co273158Synthetic
    59Co273259100%Stable
    60Co273360Synthetic
    61Co273461Synthetic
    62Co273562Synthetic
    63Co273663Synthetic
    64Co273764Synthetic
    65Co273865Synthetic
    66Co273966Synthetic
    67Co274067Synthetic
    68Co274168Synthetic
    69Co274269Synthetic
    70Co274370Synthetic
    71Co274471Synthetic
    72Co274572Synthetic
    73Co274673Synthetic
    74Co274774Synthetic
    75Co274875Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7440-48-4
    RTECS NumberRTECSGF8750000
    CID Number CID104730
    Gmelin Number-
    NSC Number-