Barium - 56Ba: 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.
![Kossel shell structure of barium](../_media/elements/electronic_configuration/electronic_configuration_Ba.png)
![Kossel shell structure of barium](../_media/elements/kossel_diagrams/kossel-atom_Ba.png)
Atomic spectrum
A representation of the atomic spectrum 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](../_media/elements/ionisation_energies/ionisation_energies_Ba.png)
Effective Nuclear Charges
The following are "Clementi-Raimondi" effective nuclear charges, Zeff. Follow the hyperlinks for more details and for graphs in various formats.
1s | 54.89 | ||||||
---|---|---|---|---|---|---|---|
2s | 41.25 | 2p | 51.81 | ||||
3s | 37.16 | 3p | 37.32 | 3d | 42.02 | ||
4s | 27.92 | 4p | 26.80 | 4d | 23.78 | 4f | (no data) |
5s | 16.62 | 5p | 14.80 | 5d | (no data) | ||
6s | 7.58 | 6p | (no data) | ||||
7s |
References
These effective nuclear charges, Zeff, are adapted from the following references:
- E. Clementi and D.L.Raimondi, J. Chem. Phys. 1963, 38, 2686.
- E. Clementi, D.L.Raimondi, and W.P. Reinhardt, J. Chem. Phys. 1967, 47, 1300.
Electron binding energies
Label | Orbital | eV [literature reference] |
---|---|---|
K | 1s | 37441 [1] |
L I | 2s | 5989 [1] |
L II | 2p1/2 | 5624 [1] |
L III | 2p3/2 | 5247 [1] |
M I | 3s | 1293 [2, values derived from reference 1] |
M II | 3p1/2 | 1137 [2, values derived from reference 1] |
M III | 3p3/2 | 1063 [2, values derived from reference 1] |
M IV | 3d3/2 | 795.7 [3] |
M V | 3d5/2 | 780.5 [2] |
N I | 4s | 253.5 [3] |
N II | 4p1/2 | 192 [1] |
N III | 4p3/2 | 178.6 [3] |
N IV | 4d3/2 | 92.6 [3] |
N V | 4d5/2 | 89.9 [3] |
N VI | 4f5/2 | - |
N VII | 4f7/2 | - |
O I | 5s | 30.3 [3] |
O II | 5p1/2 | 17 [3] |
O III | 5p3/2 | 14.8 [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
- J. A. Bearden and A. F. Burr, "Reevaluation of X-Ray Atomic Energy Levels," Rev. Mod. Phys., 1967, 39, 125.
- M. Cardona and L. Ley, Eds., Photoemission in Solids I: General Principles (Springer-Verlag, Berlin) with additional corrections, 1978.
- Gwyn Williams WWW table of values
- D.R. Lide, (Ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 81st edition, 2000.
- J. C. Fuggle and N. Mårtensson, "Core-Level Binding Energies in Metals," J. Electron Spectrosc. Relat. Phenom., 1980, 21, 275.