โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Caesium
  • ๐Ÿ‡บ๐Ÿ‡ฆ ะฆะตะทั–ะน
  • ๐Ÿ‡จ๐Ÿ‡ณ ้Šซ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Cesium
  • ๐Ÿ‡ซ๐Ÿ‡ท Césium
  • ๐Ÿ‡ฉ๐Ÿ‡ช CŠsium
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ืฆื–ื™ื•ื
  • ๐Ÿ‡ฎ๐Ÿ‡น Cesio
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใ‚ปใ‚ทใ‚ฆใƒ 
  • ๐Ÿ‡ต๐Ÿ‡น Césio
  • ๐Ÿ‡ช๐Ÿ‡ธ Cesio
  • ๐Ÿ‡ธ๐Ÿ‡ช Cesium
  • ๐Ÿ‡ท๐Ÿ‡บ ะฆะตะทะธะน

Caesium - 55Cs: properties of free atoms

Caesium atoms have 55 electrons and the shell structure is  2.8.18.18.8.1.

The ground state electron configuration of ground state gaseous neutral caesium is  [Xe].6s1 and the term symbol is  2S1/2.

Kossel shell structure of caesium
Schematic electronic configuration of caesium.
Kossel shell structure of caesium
The Kossel shell structure of caesium.

Atomic spectrum

 

A representation of the atomic spectrum of caesium.

Ionisation Energies and electron affinity

The electron affinity of caesium is 45.5 kJ mol‑1. The ionisation energies of caesium are given below.

Ionisation energies of caesium
Ionisation energy number Enthalpy / kJ mol‑1
1st375.70
2nd2234.35
3rd3202.8
4th4150
5th5400
6th6670
7th8000
8th10620
9th12120
10th20580
11th22480
12th25180 (calculated)
13th27900
14th30500
15th34000
16th36900
17th39800
18th42900
19th45900
20th57600
21st60700
Ionisation energies of caesium
Ionisation energies of caesium.

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 caesium
1s53.90  
2s40.51 2p50.82  
3s36.38 3p36.58 3d40.98  
4s27.04 4p25.86 4d22.84 4f(no data)
5s15.44 5p13.65 5d(no data)  
6s6.36 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 caesium. 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 1s35985 [1]
L I2s5714 [1]
L II2p1/25359 [1]
L III2p3/25012 [1]
M I3s1211 [2, values derived from reference 1]
M II3p1/21071 [2]
M III3p3/21003 [2]
M IV3d3/2740.5 [2]
M V3d5/2726.6 [2]
N I4s232.3 [2]
N II4p1/2172.4 [2]
N III4p3/2161.3 [2]
N IV4d3/279.8 [2]
N V4d5/277.5 [2]
N VI4f5/2 -
N VII4f7/2 -
O I5s22.7
O II5p1/214.2 [2]
O III5p3/212.1 [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.