• ๐Ÿ‡ฌ๐Ÿ‡ง Silicon
  • ๐Ÿ‡บ๐Ÿ‡ฆ ะšั€ะตะผะฝั–ะน
  • ๐Ÿ‡จ๐Ÿ‡ณ ็Ÿฝ
  • ๐Ÿ‡ณ๐Ÿ‡ฑ Silicium
  • ๐Ÿ‡ซ๐Ÿ‡ท Silicium
  • ๐Ÿ‡ฉ๐Ÿ‡ช Silicium
  • ๐Ÿ‡ฎ๐Ÿ‡ฑ ืฆื•ืจืŸ
  • ๐Ÿ‡ฎ๐Ÿ‡น Silicio
  • ๐Ÿ‡ฏ๐Ÿ‡ต ใ‚ฑใ‚ค็ด 
  • ๐Ÿ‡ต๐Ÿ‡น Silício
  • ๐Ÿ‡ช๐Ÿ‡ธ Silicio
  • ๐Ÿ‡ธ๐Ÿ‡ช Kisel
  • ๐Ÿ‡ท๐Ÿ‡บ ะšั€ะตะผะฝะธะน

Silicon isotopes are used in a variety of applications. Si-28 has been suggested to improve the thermal conductivity of semiconductors. Si-29 is used extensively in NMR spectroscopy. Si-30 has been used to produce the radioisotope Si-31. Si-30 has also been used to study the self-diffusivity of Silicon and it has been used to study the isotope effect on superconductivity.

Naturally occurring isotopes

This table shows information about naturally occuring isotopes, their atomic masses, their natural abundances, their nuclear spins, and their magnetic moments. Further data for radioisotopes (radioactive isotopes) of silicon are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
28Si 27.9769271 (7) 92.2297 (7) 0 0
29Si 28.9764949 (7) 4.6832 (5) 1/2 -0.55529
30Si 29.9737707 (7) 3.0872 (5) 0 0
Isotope abundances of silicon
Isotope abundances of silicon. In the above, the most intense ion is set to 100% since this corresponds best to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.

Radiosotope data

Further data for naturally occuring isotopes of silicon are listed above. This table gives information about some radiosotopes of silicon, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass / Da Half-life Mode of decay Nuclear spin Nuclear magnetic moment
26Si 25.992330 2.23 s EC to 26Al 0
27Si 26.9867041 4.14 s EC to 27Al 5/2
31Si 30.975362 2.62 h β- to 31P 3/2
32Si 31.974148 160 y β- to 32P 0
33Si 32.97800 6.1 s β- to 33P 3/2
34Si 33.97858 2.8 s β- to 34P 0


  1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1998 IUPAC]
  2. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides
  3. Masses, nuclear spins, and magnetic moments: I. Mills, T. Cvitas, K. Homann, N. Kallay, and K. Kuchitsu in Quantities, Units and Symbols in Physical Chemistry, Blackwell Scientific Publications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

NMR Properties of silicon

Common reference compound: Si(CH3)4/CDCl3 (1%).

Table of NMR-active nucleus propeties of silicon
  Isotope 1 Isotope 2 Isotope 3
Isotope 29Si
Natural abundance /% 4.6832
Spin (I) 1/2
Frequency relative to 1H = 100 (MHz) 19.867187
Receptivity, DP, relative to 1H = 1.00 0.000368
Receptivity, DC, relative to 13C = 1.00 2.16
Magnetogyric ratio, γ (107 rad T‑1 s-1) -5.3190
Magnetic moment, μ (μN) -0.96179
Nuclear quadrupole moment, Q/millibarn -
Line width factor, 1056 l (m4) -


  1. R.K. Harris in Encyclopedia of Nuclear Magnetic Resonance, D.M. Granty and R.K. Harris, (eds.), vol. 5, John Wiley & Sons, Chichester, UK, 1996. I am grateful to Professor Robin Harris (University of Durham, UK) who provided much of the NMR data, which are copyright 1996 IUPAC, adapted from his contribution contained within this reference.
  2. J. Mason in Multinuclear NMR, Plenum Press, New York, USA, 1987. Where given, data for certain radioactive nuclei are from this reference.
  3. P. Pyykkö, Mol. Phys., 2008, 106, 1965-1974.
  4. P. Pyykkö, Mol. Phys., 2001, 99, 1617-1629.
  5. P. Pyykkö, Z. Naturforsch., 1992, 47a, 189. I am grateful to Professor Pekka Pyykkö (University of Helsinki, Finland) who provided the nuclear quadrupole moment data in this and the following two references.
  6. D.R. Lide, (ed.), CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, USA, 79th edition, 1998.
  7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.