- 🇬🇧 Selenium
- 🇺🇦 Селен
- 🇨🇳 硒
- 🇳🇱 Selenium
- 🇫🇷 Sélénium
- 🇩🇪 Selen
- 🇮🇱 סלניום
- 🇮🇹 Selenio
- 🇯🇵 セレン
- 🇵🇹 Selênio
- 🇪🇸 Selenio
- 🇸🇪 Selen
- 🇷🇺 Селен
Selenium - 34Se: 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.
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 energy number | Enthalpy / kJ mol‑1 |
|---|---|
| 1st | 940.96 |
| 2nd | 2045.1 |
| 3rd | 3058.3 |
| 4th | 4143.8 |
| 5th | 6589.9 |
| 6th | 7895 |
| 7th | 14990 |
| 8th | 17750 |
| 9th | 21130 |
| 10th | 24600 |
| 11th | 28080 |
| 12th | 33080 (calculated) |
| 13th | 36950 |
| 14th | 41100 |
| 15th | 45640 |
| 16th | 49880 |
| 17th | 62760 |
| 18th | 66900 |
| 19th | 71380 |
| 20th | 77000 |
| 21st | 81610 |
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 | 33.2622 | ||||||
|---|---|---|---|---|---|---|---|
| 2s | 24.89 | 2p | 30.07 | ||||
| 3s | 19.40 | 3p | 18.71 | 3d | 18.48 | ||
| 4s | 9.76 | 4p | 8.29 | 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:
- 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 | 12658 [1] |
| L I | 2s | 1652 [2, values derived from reference 1] |
| L II | 2p1/2 | 1474.3 [2, values derived from reference 1] |
| L III | 2p3/2 | 1433.9 [2, values derived from reference 1] |
| M I | 3s | 229.6 [2] |
| M II | 3p1/2 | 166.5 [2] |
| M III | 3p3/2 | 160.7 [2] |
| M IV | 3d3/2 | 55.5 [2] |
| M V | 3d5/2 | 54.6 [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
- 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.