Tellurium: isotope data

Tellurium has eight stable isotopes (Te-120 and Te-123 are usually considered stable because of their long half lives) and many of them have a medical application. Te-120 is used for the production of I-120g which has an application as a PET and Beta emitting isotope. Te-122 is used in the production of the radioisotope I-122 which is used in gamma imaging. Te-123 is used for the production of radioactive I-123 which is used in thyroid imaging. Te-124 is used for the production of both I-123 and the PET isotope I-124. Finally, Te-130 is used in the research into double Beta decay.

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 tellurium are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
120Te 119.904048 (21) 0.09 (1) 0
122Te 121.903050 (3) 2.55 (12) 0
123Te 122.9042710 (22) 0.89 (3) 1/2 -0.73679
124Te 123.9028180 (18) 4.74 (14) 0
125Te 124.9044285 (25) 7.07 (15) 1/2 -0.88828
126Te 125.9033095 (25) 18.84 (25) 0
128Te 127.904463 (4) 31.74 (8) 0
130Te 129.906229 (5) 34.08 (62) 0

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 tellurium are listed above. This table gives information about some radiosotopes of tellurium, 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
116Te 115.9084 2.49 h EC to 116Sb 0
117Te 116.90864 1.03 h EC to 117Sb 1/2
118Te 117.90583 6.00 d EC to 118Sb 0
119Te 118.90641 16.0 h EC to 119Sb 1/2 0.25
121Te 120.90494 16.8 d EC to 121Sb 1/2
127Te 126.905217 9.4 h β- to 127I 3/2 0.64
129Te 128.906596 33.6 d β- to 129I 3/2 0.70

Sheffield ChemPuter isotope pattern calculator

You can use WebElements to calculate an isotope pattern for an arbitrary chemical formula:

Edit this formula :

Note the following when entering your formula:

  • Correctly nested brackets [{()}] are OK
  • 'Pseudoelements' such as Me, Ph, Cp, and many others are OK
  • Compound names and element names such as 'water' or 'manganese' are not OK
  • Experiment with your formula to see what is possible


  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 tellurium

Common reference compound: Te(CH3)2.

Table of NMR-active nucleus propeties of tellurium
  Isotope 1 Isotope 2 Isotope 3
Isotope 123Te 125Te
Natural abundance /% 0.908 7.139
Spin (I) 1/2 1/2
Frequency relative to 1H = 100 (MHz) 26.169765 31.549786
Receptivity, DP, relative to 1H = 1.00 0.000167 0.00230
Receptivity, DC, relative to 13C = 1.00 0.953 13.1
Magnetogyric ratio, γ (107 rad T‑1 s-1) -7.059098 -8.5108404
Magnetic moment, μ (μN) -1.276431 -1.5389360
Nuclear quadrupole moment, Q/millibarn - -310(20) [Mössbauer state]
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.

WebElements chemistry shop

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