There are 39 known isotopes and 17 nuclear isomers of tellurium (52Te), with atomic masses that range from 104 to 142. These are listed in the table below.

Isotopes of tellurium (52Te)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
120Te 0.09% stable
121Te synth 16.78 d ε 121Sb
122Te 2.55% stable
123Te 0.89% stable[2]
124Te 4.74% stable
125Te 7.07% stable
126Te 18.8% stable
127Te synth 9.35 h β 127I
128Te 31.7% 2.2×1024 y ββ 128Xe
129Te synth 69.6 min β 129I
130Te 34.1% 7.91×1020 y ββ 130Xe
Standard atomic weight Ar°(Te)

Naturally-occurring tellurium on Earth consists of eight isotopes. Two of these have been found to be radioactive: 128Te and 130Te undergo double beta decay with half-lives of, respectively, 2.2×1024 (2.2 septillion) years (the longest half-life of all nuclides proven to be radioactive)[5] and 8.2×1020 (820 quintillion) years. The longest-lived artificial radioisotope of tellurium is 121Te with a half-life of about 19 days. Several nuclear isomers have longer half-lives, the longest being 121mTe with a half-life of 154 days.

The very-long-lived radioisotopes 128Te and 130Te are the two most common isotopes of tellurium. Of elements with at least one stable isotope, only indium and rhenium likewise have a radioisotope in greater abundance than a stable one.

It has been claimed that electron capture of 123Te was observed, but more recent measurements of the same team have disproved this.[6] The half-life of 123Te is longer than 9.2 × 1016 years, and probably much longer.[6]

124Te can be used as a starting material in the production of radionuclides by a cyclotron or other particle accelerators. Some common radionuclides that can be produced from tellurium-124 are iodine-123 and iodine-124.

The short-lived isotope 135Te (half-life 19 seconds) is produced as a fission product in nuclear reactors. It decays, via two beta decays, to 135Xe, the most powerful known neutron absorber, and the cause of the iodine pit phenomenon.

With the exception of beryllium, tellurium is the second lightest element observed to have isotopes capable of undergoing alpha decay, with isotopes 104Te to 109Te being seen to undergo this mode of decay. Some lighter elements, namely those in the vicinity of 8Be, have isotopes with delayed alpha emission (following proton or beta emission) as a rare branch.

List of isotopes

edit
Nuclide
[n 1]
Z N Isotopic mass (Da)[7]
[n 2][n 3]
Half-life[1]
[n 4][n 5]
Decay
mode
[1]
[n 6]
Daughter
isotope

[n 7]
Spin and
parity[1]
[n 8][n 5]
Natural abundance (mole fraction)
Excitation energy Normal proportion[1] Range of variation
104Te 52 52 103.94672(34) <4 ns α 100Sn 0+
105Te 52 53 104.94330(32) 633(66) ns α 101Sn (7/2+)
106Te 52 54 105.93750(11) 78(11) μs α 102Sn 0+
107Te 52 55 106.93488(11)# 3.22(9) ms α (70%) 103Sn 5/2+#
β+ (30%) 107Sb
108Te 52 56 107.9293805(58) 2.1(1) s α (49%) 104Sn 0+
β+ (48.6%) 108Sb
β+, p (2.4%) 107Sn
β+, α (<0.065%) 104In
109Te 52 57 108.9273045(47) 4.4(2) s β+ (86.7%) 109Sb (5/2+)
β+, p (9.4%) 108Sn
α (3.9%) 105Sn
β+, α (<0.0049%) 105In
110Te 52 58 109.9224581(71) 18.6(8) s β+ 110Sb 0+
111Te 52 59 110.9210006(69) 26.2(6) s β+ 111Sb (5/2)+
β+, p (?%) 110Sn
112Te 52 60 111.9167278(90) 2.0(2) min β+ 112Sb 0+
113Te 52 61 112.915891(30) 1.7(2) min β+ 113Sb (7/2+)
114Te 52 62 113.912088(26) 15.2(7) min β+ 114Sb 0+
115Te 52 63 114.911902(30) 5.8(2) min β+ 115Sb 7/2+
115m1Te[n 9] 10(6) keV 6.7(4) min β+ 115Sb (1/2+)
115m2Te 280.05(20) keV 7.5(2) μs IT 115Te 11/2−
116Te 52 64 115.908466(26) 2.49(4) h β+ 116Sb 0+
117Te 52 65 116.908646(14) 62(2) min EC (75%) 117Sb 1/2+
β+ 117Sb
117mTe 296.1(5) keV 103(3) ms IT 117Te (11/2−)
118Te 52 66 117.905860(20) 6.00(2) d EC 118Sb 0+
119Te 52 67 118.9064057(78) 16.05(5) h EC (97.94%) 119Sb 1/2+
β+ (2.06%) 119Sb
119mTe 260.96(5) keV 4.70(4) d EC (99.59%) 119Sb 11/2−
β+ (0.41%) 119Sb
120Te 52 68 119.9040658(19) Observationally Stable[n 10] 0+ 9(1)×10−4
121Te 52 69 120.904945(28) 19.31(7) d β+ 121Sb 1/2+
121mTe 293.974(22) keV 164.7(5) d IT (88.6%) 121Te 11/2−
β+ (11.4%) 121Sb
122Te 52 70 121.9030447(15) Stable 0+ 0.0255(12)
123Te 52 71 122,9042710(15) Observationally Stable[n 11] 1/2+ 0.0089(3)
123mTe 247.47(4) keV 119.2(1) d IT 123Te 11/2−
124Te 52 72 123.9028183(15) Stable 0+ 0.0474(14)
125Te[n 12] 52 73 124.9044312(15) Stable 1/2+ 0.0707(15)
125mTe 144.775(8) keV 57.40(15) d IT 125Te 11/2−
126Te 52 74 125.9033121(15) Stable 0+ 0.1884(25)
127Te[n 12] 52 75 126.9052270(15) 9.35(7) h β 127I 3/2+
127mTe 88.23(7) keV 106.1(7) d IT (97.86%) 127Te 11/2−
β (2.14%) 127I
128Te[n 12][n 13] 52 76 127.90446124(76) 2.25(9)×1024 y[n 14] ββ 128Xe 0+ 0.3174(8)
128mTe 2790.8(3) keV 363(27) ns IT 128Te (10+)
129Te[n 12] 52 77 128.90659642(76) 69.6(3) min β 129I 3/2+
129mTe 105.51(3) keV 33.6(1) d IT (64%) 129Te 11/2−
β (36%) 129I
130Te[n 12][n 13] 52 78 129.906222745(11) 7.91(21)×1020 y ββ 130Xe 0+ 0.3408(62)
130m1Te 2146.41(4) keV 186(11) ns IT 130Te 7−
130m2Te 2667.2(8) keV 1.90(8) μs IT 130Te (10+)
130m3Te 4373.9(9) keV 53(8) ns IT 130Te (15−)
131Te[n 12] 52 79 130.908522210(65) 25.0(1) min β 131I 3/2+
131m1Te 182.258(18) keV 32.48(11) h β (74.1%) 131I 11/2−
IT (25.9%) 131Te
131m2Te 1940.0(4) keV 93(12) ms IT 131Te (23/2+)
132Te[n 12] 52 80 131.9085467(37) 3.204(13) d β 132I 0+
132m1Te 1774.80(9) keV 145(8) ns IT 132Te 6+
132m2Te 1925.47(9) keV 28.5(9) μs IT 132Te 7−
132m3Te 2723.3(8) keV 3.62(6) μs IT 132Te (10+)
133Te 52 81 132.9109633(22) 12.5(3) min β 133I 3/2+#
133m1Te 334.26(4) keV 55.4(4) min β (83.5%) 133I (11/2−)
IT (16.5%) 133Te
133m2Te 1610.4(5) keV 100(5) ns IT 133Te (19/2−)
134Te 52 82 133.9113964(29) 41.8(8) min β 134I 0+
134mTe 1691.34(16) keV 164.5(7) ns IT 134Te 6+
135Te[n 15] 52 83 134.9165547(18) 19.0(2) s β 135I (7/2−)
135mTe 1554.89(16) keV 511(20) ns IT 135Te (19/2−)
136Te 52 84 135.9201012(24) 17.63(9) s β (98.63%) 136I 0+
β, n (1.37%) 135I
137Te 52 85 136.9255994(23) 2.49(5) s β (97.06%) 137I 3/2−#
β, n (2.94%) 136I
138Te 52 86 137.9294725(41) 1.46(25) s β (95.20%) 138I 0+
β, n (4.80%) 137I
139Te 52 87 138.9353672(38) 724(81) ms β 139I 5/2−#
140Te 52 88 139.939487(15) 351(5) ms β (?%) 140I 0+
β, n (?%) 139I
141Te 52 89 140.94560(43)# 193(16) ms β 141I 5/2−#
142Te 52 90 141.95003(54)# 147(8) ms β 142I 0+
143Te 52 91 142.95649(54)# 120(8) ms β 143I 7/2+#
144Te 52 92 143.96112(32)# 93(60) ms β 144I 0+
145Te 52 93 144.96778(32)# 75# ms
[>550 ns]
β 145I
This table header & footer:
  1. ^ mTe – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ Bold half-life – nearly stable, half-life longer than age of universe.
  5. ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  6. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  7. ^ Bold symbol as daughter – Daughter product is stable.
  8. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  9. ^ Order of ground state and isomer is uncertain.
  10. ^ Believed to undergo β+β+ decay to 120Sn with a half-life over 1.6×1021 years
  11. ^ Believed to undergo electron capture to 123Sb with a half-life over 9.2×1016 years
  12. ^ a b c d e f g Fission product
  13. ^ a b Primordial radionuclide
  14. ^ Longest measured half-life of any nuclide
  15. ^ Very short-lived fission product, responsible for the iodine pit as precursor of 135Xe via 135I

References

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  1. ^ a b c d e Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ Alessandrello, A.; Arnaboldi, C.; Brofferio, C.; Capelli, S.; Cremonesi, O.; Fiorini, E.; Nucciotti, A.; Pavan, M.; Pessina, G.; Pirro, S.; Previtali, E.; Sisti, M.; Vanzini, M.; Zanotti, L.; Giuliani, A.; Pedretti, M.; Bucci, C.; Pobes, C. (2003). "New limits on naturally occurring electron capture of 123Te". Physical Review C. 67: 014323. arXiv:hep-ex/0211015. Bibcode:2003PhRvC..67a4323A. doi:10.1103/PhysRevC.67.014323.
  3. ^ "Standard Atomic Weights: Tellurium". CIAAW. 1969.
  4. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  5. ^ Many isotopes are expected to have longer half-lives, but decay has not yet been observed in these, allowing only a lower limit to be placed on their half-lives
  6. ^ a b A. Alessandrello; et al. (January 2003). "New Limits on Naturally Occurring Electron Capture of 123Te". Physical Review C. 67 (1): 014323. arXiv:hep-ex/0211015. Bibcode:2003PhRvC..67a4323A. doi:10.1103/PhysRevC.67.014323. S2CID 119523039.
  7. ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.