Barium: properties of free atoms

Barium atoms have 56 electrons and the shell structure is  2.8.18.18.8.2.

The ground state electron configuration of ground state gaseous neutral barium is  [Xe].6s2 and the term symbol is  1S0.

Atomic spectrum

 

A representation of the atomic spectrum of barium.

Electronic configuration of neutral atomic barium

Electronic configuration of barium

The electronic configuration of barium.

Kossel shell structure of barium

The Kossel shell structure of barium.

Ionisation Energies and electron affinity

The electron affinity of barium is 13.95 kJ mol‑1. The ionisation energies of barium are given below.

Ionisation energies of barium
Ionisation energy number Enthalpy / kJ mol‑1
1st502.9
2nd965.2
3rd3600

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 barium
1s54.89  
2s41.25 2p51.81  
3s37.16 3p37.32 3d42.02  
4s27.92 4p26.80 4d23.78 4f(no data)
5s16.62 5p14.80 5d(no data)  
6s7.58 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 barium. 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 1s37441 [1]
L I2s5989 [1]
L II2p1/25624 [1]
L III2p3/25247 [1]
M I3s1293 [2, values derived from reference 1]
M II3p1/21137 [2, values derived from reference 1]
M III3p3/21063 [2, values derived from reference 1]
M IV3d3/2795.7 [3]
M V3d5/2780.5 [2]
N I4s253.5 [3]
N II4p1/2192 [1]
N III4p3/2178.6 [3]
N IV4d3/292.6 [3]
N V4d5/289.9 [3]
N VI4f5/2 -
N VII4f7/2 -
O I5s30.3 [3]
O II5p1/217 [3]
O III5p3/214.8 [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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