Argon - ₁₈Ar: 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.

Ionisation Energies and electron affinity

The electron affinity of argon is 0 kJ mol^‑1. The ionisation energies of argon are given below.

Effective Nuclear Charges

The following are "Clementi-Raimondi" effective nuclear charges, Z_eff. Follow the hyperlinks for more details and for graphs in various formats.

References

These effective nuclear charges, Z_eff, 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

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.