Hydrogen - 1H: properties of free atoms
Hydrogen atoms have 1 electron and the shell structure is 1.
The ground state electron configuration of ground state gaseous neutral hydrogen is 1s1 and the term symbol is 2S1/2.
A representation of the atomic spectrum of hydrogen.
Ionisation Energies and electron affinity
The electron affinity of hydrogen is 72.8 kJ mol‑1. The ionisation energies of hydrogen are given below.
|Ionisation energy number||Enthalpy / kJ mol‑1|
Effective Nuclear Charges
The following are "Clementi-Raimondi" effective nuclear charges, Zeff. Follow the hyperlinks for more details and for graphs in various formats.
|2s||(no data)||2p||(no data)|
|3s||(no data)||3p||(no data)||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)|
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]|
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).
- 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.