Potassium: properties of free atoms

Potassium atoms have 19 electrons and the shell structure is  2.8.8.1.

The ground state electron configuration of ground state gaseous neutral potassium is  [Ar].4s1 and the term symbol is  2S1/2.

Atomic spectrum

 

A representation of the atomic spectrum of potassium.

Electronic configuration of neutral atomic potassium

Electronic configuration of potassium

The electronic configuration of potassium.

Kossel shell structure of potassium

The Kossel shell structure of potassium.

Ionisation Energies and electron affinity

The electron affinity of potassium is 48.4 kJ mol‑1. The ionisation energies of potassium are given below.

Ionisation energies of potassium
Ionisation energy number Enthalpy / kJ mol‑1
1st418.8
2nd3052
3rd4420
4th5877
5th7975
6th9590
7th11343
8th14944
9th16963.7
10th48610
11th54490
12th60730
13th68950
14th75900
15th83080
16th93400
17th99710
18th444870
19th476061

Effective Nuclear Charges

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

Effective nuclear charges for potassium
1s18.49  
2s13.01 2p15.03  
3s8.68 3p7.73 3d(no data)  
4s3.50 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:

  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

Electron binding energies for potassium. All values of electron binding energies are given in eV. The binding energies are quoted relative to the vacuum level for rare gases and H2, N2, O2, F2, and Cl2 molecules; relative to the Fermi level for metals; and relative to the top of the valence band for semiconductors.
Label Orbital eV [literature reference]
K 1s3608.4 [2]
L I2s378.6 [2]
L II2p1/2297.3 [2]
L III2p3/2294.6 [2]
M I3s34.8 [2]
M II3p1/218.3 [2]
M III3p3/218.3 [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

  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.

WebElements Shop

You can buy periodic table posters, mugs, T-shirts, fridge magnets, games, molecular models, and more at the WebElements shop