Argon: properties of free atoms
Argon atoms have 18 electrons and the shell structure is 2.8.8.
The ground state electron configuration of ground state gaseous neutral argon is [Ne].3s2.3p6 and the term symbol is 1S0.
Atomic spectrum
A representation of the atomic spectrum of argon.
Electronic configuration of neutral atomic argon
The electronic configuration of argon.
The Kossel shell structure of argon.
Ionisation Energies and electron affinity
The electron affinity of argon is 0 kJ mol‑1. The ionisation energies of argon are given below.
| Ionisation energy number | Enthalpy / kJ mol‑1 |
|---|---|
| 1st | 1520.6 |
| 2nd | 2665.8 |
| 3rd | 3931 |
| 4th | 5771 |
| 5th | 7238 |
| 6th | 8781 |
| 7th | 11995 |
| 8th | 13842 |
| 9th | 40760 |
| 10th | 46186 |
| 11th | 52002 |
| 12th | 59653 |
| 13th | 66198 |
| 14th | 72918 |
| 15th | 82472 |
| 16th | 88576 |
| 17th | 397604 |
| 18th | 427065 |
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 | 17.51 | ||||||
|---|---|---|---|---|---|---|---|
| 2s | 12.23 | 2p | 14.01 | ||||
| 3s | 7.76 | 3p | 6.76 | 3d | (no data) | ||
| 4s | (no data) | 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:
- 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 | 3205.9 [2] |
| L I | 2s | 326.3 [2] |
| L II | 2p1/2 | 250.6 [3] |
| L III | 2p3/2 | 248.4 [2] |
| M I | 3s | 29.3 [2] |
| M II | 3p1/2 | 15.9 [2] |
| M III | 3p3/2 | 15.7 [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.
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