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. 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 Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

of, respectively, 2.2×10²⁴ (2.2

septillion Two naming scales for large numbers have been used in English and other European languages since the early modern era: the long and short scales. Most English variants use the short scale today, but the long scale remains dominant in many non-Eng ...

) years (the longest half-life of all nuclides proven to be radioactive)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 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 the recent measurements of the same team have disproved this. The half-life of ¹²³Te is longer than 9.2 × 10¹⁶ years, and probably much longer. 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 There are 37 known isotopes of iodine (53I) from 108I to 144I; all undergo radioactive decay except 127I, which is stable. Iodine is thus a monoisotopic element. Its longest-lived radioactive isotope, 129I, has a half-life of 15.7 million year ...

. The short-lived isotope ¹³⁵Te (half-life 19 seconds) is produced as a

fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release ...

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 lightest element observed to commonly undergo 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 A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

or beta emission) as a rare branch.

List of isotopes

, - , ¹⁰⁴Te , style="text-align:right" , 52 , style="text-align:right" , 52 , , <18 ns , α , ¹⁰⁰Sn , 0+ , , , - , ¹⁰⁵Te , style="text-align:right" , 52 , style="text-align:right" , 53 , 104.94364(54)# , 620(70) ns , α , ¹⁰¹Sn , 5/2+# , , , - , ¹⁰⁶Te , style="text-align:right" , 52 , style="text-align:right" , 54 , 105.93750(14) , 70(20) µs
0(+20−10) µs, α , ¹⁰²Sn , 0+ , , , - , rowspan=2, ¹⁰⁷Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 55 , rowspan=2, 106.93501(32)# , rowspan=2, 3.1(1) ms , α (70%) , ¹⁰³Sn , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , β⁺ (30%) , ¹⁰⁷Sb , - , rowspan=4, ¹⁰⁸Te , rowspan=4 style="text-align:right" , 52 , rowspan=4 style="text-align:right" , 56 , rowspan=4, 107.92944(11) , rowspan=4, 2.1(1) s , α (49%) , ¹⁰⁴Sn , rowspan=4, 0+ , rowspan=4, , rowspan=4, , - , β⁺ (48.5%) , ¹⁰⁸Sb , - , β⁺, p (2.4%) , ¹⁰⁷Sn , - , β⁺, α (.065%) , ¹⁰⁴In , - , rowspan=4, ¹⁰⁹Te , rowspan=4 style="text-align:right" , 52 , rowspan=4 style="text-align:right" , 57 , rowspan=4, 108.92742(7) , rowspan=4, 4.6(3) s , β⁺ (86.99%) , ¹⁰⁹Sb , rowspan=4, (5/2+) , rowspan=4, , rowspan=4, , - , β⁺, p (9.4%) , ¹⁰⁸Sn , - , α (7.9%) , ¹⁰⁵Sn , - , β⁺, α (.005%) , ¹⁰⁵In , - , rowspan=2, ¹¹⁰Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 58 , rowspan=2, 109.92241(6) , rowspan=2, 18.6(8) s , β⁺ (99.99%) , ¹¹⁰Sb , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺, p (.003%) , ¹⁰⁹Sn , - , rowspan=2, ¹¹¹Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 59 , rowspan=2, 110.92111(8) , rowspan=2, 19.3(4) s , β⁺ , ¹¹¹Sb , rowspan=2, (5/2)+# , rowspan=2, , rowspan=2, , - , β⁺, p (rare) , ¹¹⁰Sn , - , ¹¹²Te , style="text-align:right" , 52 , style="text-align:right" , 60 , 111.91701(18) , 2.0(2) min , β⁺ , ¹¹²Sb , 0+ , , , - , ¹¹³Te , style="text-align:right" , 52 , style="text-align:right" , 61 , 112.91589(3) , 1.7(2) min , β⁺ , ¹¹³Sb , (7/2+) , , , - , ¹¹⁴Te , style="text-align:right" , 52 , style="text-align:right" , 62 , 113.91209(3) , 15.2(7) min , β⁺ , ¹¹⁴Sb , 0+ , , , - , ¹¹⁵Te , style="text-align:right" , 52 , style="text-align:right" , 63 , 114.91190(3) , 5.8(2) min , β⁺ , ¹¹⁵Sb , 7/2+ , , , - , rowspan=2 style="text-indent:1em" , ^115m1Te , rowspan=2 colspan="3" style="text-indent:2em" , 10(7) keV , rowspan=2, 6.7(4) min , β⁺ , ¹¹⁵Sb , rowspan=2, (1/2)+ , rowspan=2, , rowspan=2, , - , IT , ¹¹⁵Te , - , style="text-indent:1em" , ^115m2Te , colspan="3" style="text-indent:2em" , 280.05(20) keV , 7.5(2) µs , , , 11/2− , , , - , ¹¹⁶Te , style="text-align:right" , 52 , style="text-align:right" , 64 , 115.90846(3) , 2.49(4) h , β⁺ , ¹¹⁶Sb , 0+ , , , - , ¹¹⁷Te , style="text-align:right" , 52 , style="text-align:right" , 65 , 116.908645(14) , 62(2) min , β⁺ , ¹¹⁷Sb , 1/2+ , , , - , style="text-indent:1em" , ^117mTe , colspan="3" style="text-indent:2em" , 296.1(5) keV , 103(3) ms , IT , ¹¹⁷Te , (11/2−) , , , - , ¹¹⁸Te , style="text-align:right" , 52 , style="text-align:right" , 66 , 117.905828(16) , 6.00(2) d , EC , ¹¹⁸Sb , 0+ , , , - , ¹¹⁹Te , style="text-align:right" , 52 , style="text-align:right" , 67 , 118.906404(9) , 16.05(5) h , β⁺ , ¹¹⁹Sb , 1/2+ , , , - , rowspan=2 style="text-indent:1em" , ^119mTe , rowspan=2 colspan="3" style="text-indent:2em" , 260.96(5) keV , rowspan=2, 4.70(4) d , β⁺ (99.99%) , ¹¹⁹Sb , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , IT (.008%) , ¹¹⁹Te , - , ¹²⁰Te , style="text-align:right" , 52 , style="text-align:right" , 68 , 119.90402(1) , colspan=3 align=center, Observationally StableBelieved to undergo β⁺β⁺ decay to ¹²⁰Sn with a half-life over 2.2×10¹⁶ years , 0+ , 9(1)×10⁻⁴ , , - , ¹²¹Te , style="text-align:right" , 52 , style="text-align:right" , 69 , 120.904936(28) , 19.16(5) d , β⁺ , ¹²¹Sb , 1/2+ , , , - , rowspan=2 style="text-indent:1em" , ^121mTe , rowspan=2 colspan="3" style="text-indent:2em" , 293.991(22) keV , rowspan=2, 154(7) d , IT (88.6%) , ¹²¹Te , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , β⁺ (11.4%) , ¹²¹Sb , - , ¹²²Te , style="text-align:right" , 52 , style="text-align:right" , 70 , 121.9030439(16) , colspan=3 align=center, StableTheoretically capable of

spontaneous fission Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements. The nuclear binding energy of the elements reaches its maximum at an atomic mass number of about 56 (e.g., iron-56); spontaneous breakdo ...

, 0+ , 0.0255(12) , , - , ¹²³Te , style="text-align:right" , 52 , style="text-align:right" , 71 , 122.9042700(16) , colspan=3 align=center, Observationally StableBelieved to undergo β⁺ decay to ¹²³Sb with a half-life over 9.2×10¹⁶ years , 1/2+ , 0.0089(3) , , - , style="text-indent:1em" , ^123mTe , colspan="3" style="text-indent:2em" , 247.47(4) keV , 119.2(1) d , IT , ¹²³Te , 11/2− , , , - , ¹²⁴Te , style="text-align:right" , 52 , style="text-align:right" , 72 , 123.9028179(16) , colspan=3 align=center, Stable , 0+ , 0.0474(14) , , - , ¹²⁵Te

Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release ...

, style="text-align:right" , 52 , style="text-align:right" , 73 , 124.9044307(16) , colspan=3 align=center, Stable , 1/2+ , 0.0707(15) , , - , style="text-indent:1em" , ^125mTe , colspan="3" style="text-indent:2em" , 144.772(9) keV , 57.40(15) d , IT , ¹²⁵Te , 11/2− , , , - , ¹²⁶Te , style="text-align:right" , 52 , style="text-align:right" , 74 , 125.9033117(16) , colspan=3 align=center, Stable , 0+ , 0.1884(25) , , - , ¹²⁷Te , style="text-align:right" , 52 , style="text-align:right" , 75 , 126.9052263(16) , 9.35(7) h , β⁻ , ¹²⁷I , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^127mTe , rowspan=2 colspan="3" style="text-indent:2em" , 88.26(8) keV , rowspan=2, 109(2) d , IT (97.6%) , ¹²⁷Te , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , β⁻ (2.4%) , ¹²⁷I , - , ¹²⁸Te

Primordial Primordial may refer to: * Primordial era, an era after the Big Bang. See Chronology of the universe * Primordial sea (a.k.a. primordial ocean, ooze or soup). See Abiogenesis * Primordial nuclide, nuclides, a few radioactive, that formed before ...

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transfer ...

, style="text-align:right" , 52 , style="text-align:right" , 76 , 127.9044631(19) , 2.2(3)×10²⁴ yLongest measured half-life of any nuclide , β⁻β⁻ , ¹²⁸Xe , 0+ , 0.3174(8) , , - , style="text-indent:1em" , ^128mTe , colspan="3" style="text-indent:2em" , 2790.7(4) keV , 370(30) ns , , , 10+ , , , - , ¹²⁹Te , style="text-align:right" , 52 , style="text-align:right" , 77 , 128.9065982(19) , 69.6(3) min , β⁻ , ¹²⁹I , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^129mTe , rowspan=2 colspan="3" style="text-indent:2em" , 105.50(5) keV , rowspan=2 , 33.6(1) d , β⁻ (36%) , ¹²⁹I , rowspan=2 , 11/2− , rowspan=2 , , rowspan=2 , , - , IT (64%) , ¹²⁹Te , - , ¹³⁰Te , style="text-align:right" , 52 , style="text-align:right" , 78 , 129.9062244(21) , 8.2(0.2 (stat.), 0.6 (syst.)) y , β⁻β⁻ , ¹³⁰Xe , 0+ , 0.3408(62) , , - , style="text-indent:1em" , ^130m1Te , colspan="3" style="text-indent:2em" , 2146.41(4) keV , 115(8) ns , , , (7)− , , , - , style="text-indent:1em" , ^130m2Te , colspan="3" style="text-indent:2em" , 2661(7) keV , 1.90(8) µs , , , (10+) , , , - , style="text-indent:1em" , ^130m3Te , colspan="3" style="text-indent:2em" , 4375.4(18) keV , 261(33) ns , , , , , , - , ¹³¹Te , style="text-align:right" , 52 , style="text-align:right" , 79 , 130.9085239(21) , 25.0(1) min , β⁻ , ¹³¹I , 3/2+ , , , - , rowspan=2 style="text-indent:1em" , ^131mTe , rowspan=2 colspan="3" style="text-indent:2em" , 182.250(20) keV , rowspan=2, 30(2) h , β⁻ (77.8%) , ¹³¹I , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , IT (22.2%) , ¹³¹Te , - , ¹³²Te , style="text-align:right" , 52 , style="text-align:right" , 80 , 131.908553(7) , 3.204(13) d , β⁻ , ¹³²I , 0+ , , , - , ¹³³Te , style="text-align:right" , 52 , style="text-align:right" , 81 , 132.910955(26) , 12.5(3) min , β⁻ , ¹³³I , (3/2+) , , , - , rowspan=2 style="text-indent:1em" , ^133mTe , rowspan=2 colspan="3" style="text-indent:2em" , 334.26(4) keV , rowspan=2, 55.4(4) min , β⁻ (82.5%) , ¹³³I , rowspan=2, (11/2−) , rowspan=2, , rowspan=2, , - , IT (17.5%) , ¹³³Te , - , ¹³⁴Te , style="text-align:right" , 52 , style="text-align:right" , 82 , 133.911369(11) , 41.8(8) min , β⁻ , ¹³⁴I , 0+ , , , - , style="text-indent:1em" , ^134mTe , colspan="3" style="text-indent:2em" , 1691.34(16) keV , 164.1(9) ns , , , 6+ , , , - , ¹³⁵TeVery short-lived

, responsible for the iodine pit as precursor of ¹³⁵Xe via ¹³⁵I , style="text-align:right" , 52 , style="text-align:right" , 83 , 134.91645(10) , 19.0(2) s , β⁻ , ¹³⁵I , (7/2−) , , , - , style="text-indent:1em" , ^135mTe , colspan="3" style="text-indent:2em" , 1554.88(17) keV , 510(20) ns , , , (19/2−) , , , - , rowspan=2, ¹³⁶Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 84 , rowspan=2, 135.92010(5) , rowspan=2, 17.63(8) s , β⁻ (98.7%) , ¹³⁶I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (1.3%) , ¹³⁵I , - , rowspan=2, ¹³⁷Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 85 , rowspan=2, 136.92532(13) , rowspan=2, 2.49(5) s , β⁻ (97.01%) , ¹³⁷I , rowspan=2, 3/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (2.99%) , ¹³⁶I , - , rowspan=2, ¹³⁸Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 86 , rowspan=2, 137.92922(22)# , rowspan=2, 1.4(4) s , β⁻ (93.7%) , ¹³⁸I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n (6.3%) , ¹³⁷I , - , rowspan=2, ¹³⁹Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 87 , rowspan=2, 138.93473(43)# , rowspan=2, 500 ms
300 ns , β⁻ , ¹³⁹I , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁻, n , ¹³⁸I , - , rowspan=2, ¹⁴⁰Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 88 , rowspan=2, 139.93885(32)# , rowspan=2, 300 ms
300 ns , β⁻ , ¹⁴⁰I , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁻, n , ¹³⁹I , - , rowspan=2, ¹⁴¹Te , rowspan=2 style="text-align:right" , 52 , rowspan=2 style="text-align:right" , 89 , rowspan=2, 140.94465(43)# , rowspan=2, 100 ms
300 ns , β⁻ , ¹⁴¹I , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁻, n , ¹⁴⁰I , - , ¹⁴²Te , style="text-align:right" , 52 , style="text-align:right" , 90 , 141.94908(64)# , 50 ms
300 ns , β⁻ , ¹⁴²I , 0+ , ,

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** ** {{Navbox element isotopes Tellurium Tellurium