โ–ธโ–ธ
  • ๐Ÿ‡ฌ๐Ÿ‡ง Boron
  • ๐Ÿ‡บ๐Ÿ‡ฆ ะ‘ะพั€
  • ๐Ÿ‡จ๐Ÿ‡ณ ็กผ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Boor
  • ๐Ÿ‡ซ๐Ÿ‡ท Bore
  • ๐Ÿ‡ฉ๐Ÿ‡ช Bor
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ื‘ื•ืจ
  • ๐Ÿ‡ฎ๐Ÿ‡น Boro
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใƒ›ใ‚ฆ็ด 
  • ๐Ÿ‡ต๐Ÿ‡น Boro
  • ๐Ÿ‡ช๐Ÿ‡ธ Boro
  • ๐Ÿ‡ธ๐Ÿ‡ช Bor
  • ๐Ÿ‡ท๐Ÿ‡บ ะ‘ะพั€

Boron - 5B: properties of free atoms

Boron atoms have 5 electrons and the shell structure is  2.3.

The ground state electron configuration of ground state gaseous neutral boron is  [He].2s2.2p1 and the term symbol is  2P1/2.

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

Atomic spectrum

 

A representation of the atomic spectrum of boron.

Ionisation Energies and electron affinity

The electron affinity of boron is 26.7 0.279723(25) eV kJ mol‑1. The ionisation energies of boron are given below.

Ionisation energies of boron
Ionisation energy number Enthalpy / kJ mol‑1
1st800.64
2nd2427.07
3rd3659.74
4th25025.54
5th32826.8
Ionisation energies of boron
Ionisation energies of boron.

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 boron
1s4.6795  
2s2.58 2p2.42  
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)  
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 boron. 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 1s188 [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.