Cobalt: properties of free atoms

Cobalt atoms have 27 electrons and the shell structure is  2.8.15.2.

The ground state electron configuration of ground state gaseous neutral cobalt is  [Ar].3d7.4s2 and the term symbol is  4F9/2.

Atomic spectrum

 

A representation of the atomic spectrum of cobalt.

Electronic configuration of neutral atomic cobalt

Electronic configuration of cobalt

The electronic configuration of cobalt.

Kossel shell structure of cobalt

The Kossel shell structure of cobalt.

Ionisation Energies and electron affinity

The electron affinity of cobalt is 63.7 kJ mol‑1. The ionisation energies of cobalt are given below.

Ionisation energies of cobalt
Ionisation energy number Enthalpy / kJ mol‑1
1st760.4
2nd1648
3rd3232
4th4950
5th7670
6th9840
7th12440
8th15230
9th17959
10th26570
11th29400
12th32400
13th36600
14th39700
15th42800
16th49396
17th52737
18th134810
19th145170
20th154700
21st167400

Effective Nuclear Charges

The following are "Clementi-Raimondi" effective nuclear charges, Zeff. Follow the hyperlinks for more details and for graphs in various formats.

Effective nuclear charges for cobalt
1s26.37  
2s19.41 2p23.09  
3s14.32 3p13.43 3d11.86  
4s5.58 4p(no data) 4d(no data) 4f(no data)
5s(no data) 5p(no data) 5d(no data)  
6s(no data) 6p(no data)  
7s   

References

These effective nuclear charges, Zeff, are adapted from the following references:

  1. E. Clementi and D.L.Raimondi, J. Chem. Phys. 1963, 38, 2686.
  2. E. Clementi, D.L.Raimondi, and W.P. Reinhardt, J. Chem. Phys. 1967, 47, 1300.

Electron binding energies

Electron binding energies for cobalt. All values of electron binding energies are given in eV. The binding energies are quoted relative to the vacuum level for rare gases and H2, N2, O2, F2, and Cl2 molecules; relative to the Fermi level for metals; and relative to the top of the valence band for semiconductors.
Label Orbital eV [literature reference]
K 1s7709 [1]
L I2s925.1 [3]
L II2p1/2793.2 [3]
L III2p3/2778.1 [3]
M I3s101 [3]
M II3p1/258.9 [3]
M III3p3/259.9 [3]

Notes

I am grateful to Gwyn Williams (Jefferson Laboratory, Virginia, USA) who provided the electron binding energy data. The data are adapted from references 1-3. They are tabulated elsewhere on the WWW (reference 4) and in paper form (reference 5).

References

  1. J. A. Bearden and A. F. Burr, "Reevaluation of X-Ray Atomic Energy Levels," Rev. Mod. Phys., 1967, 39, 125.
  2. M. Cardona and L. Ley, Eds., Photoemission in Solids I: General Principles (Springer-Verlag, Berlin) with additional corrections, 1978.
  3. Gwyn Williams WWW table of values
  4. D.R. Lide, (Ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 81st edition, 2000.
  5. J. C. Fuggle and N. Mårtensson, "Core-Level Binding Energies in Metals," J. Electron Spectrosc. Relat. Phenom., 1980, 21, 275.

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