Selenium: properties of free atoms

Selenium atoms have 34 electrons and the shell structure is  2.8.18.6.

The ground state electron configuration of ground state gaseous neutral selenium is  [Ar].3d10.4s2.4p4 and the term symbol is  3P2.

Atomic spectrum

 

A representation of the atomic spectrum of selenium.

Electronic configuration of neutral atomic selenium

Electronic configuration of selenium

The electronic configuration of selenium.

Kossel shell structure of selenium

The Kossel shell structure of selenium.

Ionisation Energies and electron affinity

The electron affinity of selenium is 195.0 kJ mol‑1. The ionisation energies of selenium are given below.

Ionisation energies of selenium
Ionisation energy number Enthalpy / kJ mol‑1
1st941.0
2nd2045
3rd2973.7
4th4144
5th6590
6th7880
7th14990

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 selenium
1s33.26  
2s24.89 2p30.07  
3s19.40 3p18.71 3d18.48  
4s9.76 4p8.29 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 selenium. 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 1s12658 [1]
L I2s1652 [2, values derived from reference 1]
L II2p1/21474.3 [2, values derived from reference 1]
L III2p3/21433.9 [2, values derived from reference 1]
M I3s229.6 [2]
M II3p1/2166.5 [2]
M III3p3/2160.7 [2]
M IV3d3/255.5 [2]
M V3d5/254.6 [2]

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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