Isotopes of tellurium
Encyclopedia
There are 38 known isotope
s and 17 nuclear isomer
s of tellurium (Te) with atomic mass
es that range from 105 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
of, respectively, 2.2×1024 (2.2 septillion) years (the longest half-life of all nuclides proven to be radioactive) and 7.9×1020 (790 quintillion) years. The longest-lived artificial radioisotope is 121Te with a half-life of 19.16 days. Several 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.
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 decay
s, to 135Xe, the most powerful known neutron absorber, and the cause of the iodine pit
phenomenon.
Tellurium is the lightest element observed to commonly undergo alpha decay
, with isotopes 106Te to 110Te being seen to undergo this mode of decay. (Some lighter elements have isotopes with alpha decay as a rare branch)
Tellurium's standard atomic mass is: 127.60(3) u.
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
s and 17 nuclear isomer
Nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus caused by the excitation of one or more of its nucleons . "Metastable" refers to the fact that these excited states have half-lives more than 100 to 1000 times the half-lives of the other possible excited nuclear states...
s of tellurium (Te) with atomic mass
Atomic mass
The atomic mass is the mass of a specific isotope, most often expressed in unified atomic mass units. The atomic mass is the total mass of protons, neutrons and electrons in a single atom....
es that range from 105 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
Radionuclide
A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma...
: 128Te and 130Te undergo double beta decay
Double beta decay
Double beta decay is a radioactive decay process where a nucleus releases two beta rays as a single process.In double-beta decay, two neutrons in the nucleus are converted to protons, and two electrons and two electron antineutrinos are emitted...
with half-lives
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of, respectively, 2.2×1024 (2.2 septillion) years (the longest half-life of all nuclides proven to be radioactive) and 7.9×1020 (790 quintillion) years. The longest-lived artificial radioisotope is 121Te with a half-life of 19.16 days. Several 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
Indium
Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible post-transition metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two...
and rhenium
Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion , rhenium is one of the rarest elements in the Earth's crust. The free element has...
likewise have a radioisotope in greater abundance than a stable one.
It has been claimed that electron capture
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...
of 123Te was observed, but the recent measurements of the same team have disproved this.
124Te can be used as a starting material in the production of radionuclides by a cyclotron
Cyclotron
In technology, a cyclotron is a type of particle accelerator. In physics, the cyclotron frequency or gyrofrequency is the frequency of a charged particle moving perpendicularly to the direction of a uniform magnetic field, i.e. a magnetic field of constant magnitude and direction...
or other particle accelerators. Some common radionuclides that can be produced from tellurium-124 are Iodine-123
Iodine-123
Iodine-123 is a radioactive isotope of iodine used in nuclear medicine imaging, including single photon emission computed tomography . The isotope's half-life is 13.22 hours; the decay by electron capture to tellurium-123 emits gamma radiation with predominant energies of 159 keV and 127 keV...
and Iodine-124.
The short-lived isotope 135Te (half-life 19 seconds) is produced as a fission product
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...
in nuclear reactors. It decays, via two beta decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
s, to 135Xe, the most powerful known neutron absorber, and the cause of the iodine pit
Iodine pit
Iodine pit, also called iodine hole and xenon pit, is a temporary disabling of a nuclear reactor due to buildup of short-lived nuclear poisons in the core of a nuclear reactor. The main isotope responsible is xenon-135, mainly produced by natural decay of iodine-135. Iodine-135 is a weak neutron...
phenomenon.
Tellurium is the lightest element observed to commonly undergo alpha decay
Alpha decay
Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less...
, with isotopes 106Te to 110Te being seen to undergo this mode of decay. (Some lighter elements have isotopes with alpha decay as a rare branch)
Tellurium's standard atomic mass is: 127.60(3) u.
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-lifeBold for isotopes with half-lives longer than the age of the universe (nearly stable) | decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 105Te | 52 | 53 | 104.94364(54)# | 1 µs# | 5/2+# | ||||
| 106Te | 52 | 54 | 105.93750(14) | 70(20) µs [70(+20-10) µs] |
α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... |
102Sn | 0+ | ||
| 107Te | 52 | 55 | 106.93501(32)# | 3.1(1) ms | α (70%) | 103Sn | 5/2+# | ||
| β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... (30%) |
107Sb | ||||||||
| 108Te | 52 | 56 | 107.92944(11) | 2.1(1) s | β+ (51%) | 108Sb | 0+ | ||
| α (49%) | 104Sn | ||||||||
| β+, p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... (2.4%) |
108Sb | ||||||||
| β+, α (.065%) | 104In | ||||||||
| 109Te | 52 | 57 | 108.92742(7) | 4.6(3) s | β+ (86.99%) | 109Sb | (5/2+) | ||
| β+, p (9.4%) | 108Sn | ||||||||
| α (7.9%) | 105Sn | ||||||||
| β+, α (.005%) | 105In | ||||||||
| 110Te | 52 | 58 | 109.92241(6) | 18.6(8) s | β+ (99.99%) | 110Sb | 0+ | ||
| β+, p (.003%) | 109Sn | ||||||||
| 111Te | 52 | 59 | 110.92111(8) | 19.3(4) s | β+ | 111Sb | (5/2)+# | ||
| β+, p (rare) | 110Sn | ||||||||
| 112Te | 52 | 60 | 111.91701(18) | 2.0(2) min | β+ | 112Sb | 0+ | ||
| 113Te | 52 | 61 | 112.91589(3) | 1.7(2) min | β+ | 113Sb | (7/2+) | ||
| 114Te | 52 | 62 | 113.91209(3) | 15.2(7) min | β+ | 114Sb | 0+ | ||
| 115Te | 52 | 63 | 114.91190(3) | 5.8(2) min | β+ | 115Sb | 7/2+ | ||
| 115m1Te | 10(7) keV | 6.7(4) min | β+ | 115Sb | (1/2)+ | ||||
| IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
115Te | ||||||||
| 115m2Te | 280.05(20) keV | 7.5(2) µs | 11/2- | ||||||
| 116Te | 52 | 64 | 115.90846(3) | 2.49(4) h | β+ | 116Sb | 0+ | ||
| 117Te | 52 | 65 | 116.908645(14) | 62(2) min | β+ | 117Sb | 1/2+ | ||
| 117mTe | 296.1(5) keV | 103(3) ms | IT | 117Te | (11/2-) | ||||
| 118Te | 52 | 66 | 117.905828(16) | 6.00(2) d | EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... |
118Sb | 0+ | ||
| 119Te | 52 | 67 | 118.906404(9) | 16.05(5) h | β+ | 119Sb | 1/2+ | ||
| 119mTe | 260.96(5) keV | 4.70(4) d | β+ (99.99%) | 119Sb | 11/2- | ||||
| IT (.008%) | 119Te | ||||||||
| 120Te | 52 | 68 | 119.90402(1) | Observationally StableBelieved to undergo β+β+ decay to 120Sn with a half-life over 2.2×1016 years | 0+ | 9(1)×10−4 | |||
| 121Te | 52 | 69 | 120.904936(28) | 19.16(5) d | β+ | 121Sb | 1/2+ | ||
| 121mTe | 293.991(22) keV | 154(7) d | IT (88.6%) | 121Te | 11/2- | ||||
| β+ (11.4%) | 121Sb | ||||||||
| 122Te | 52 | 70 | 121.9030439(16) | Observationally StableTheoretically capable of spontaneous fission Spontaneous fission Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses... |
0+ | 0.0255(12) | |||
| 123Te | 52 | 71 | 122.9042700(16) | Observationally StableBelieved to undergo β+ decay to 123Sb with a half-life over 600×1012 years | 1/2+ | 0.0089(3) | |||
| 123mTe | 247.47(4) keV | 119.2(1) d | IT | 123Te | 11/2- | ||||
| 124Te | 52 | 72 | 123.9028179(16) | Observationally Stable | 0+ | 0.0474(14) | |||
| 125TeFission product Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The... |
52 | 73 | 124.9044307(16) | Observationally Stable | 1/2+ | 0.0707(15) | |||
| 125mTe | 144.772(9) keV | 57.40(15) d | IT | 125Te | 11/2- | ||||
| 126Te | 52 | 74 | 125.9033117(16) | Observationally Stable | 0+ | 0.1884(25) | |||
| 127Te | 52 | 75 | 126.9052263(16) | 9.35(7) h | β- | 127I | 3/2+ | ||
| 127mTe | 88.26(8) keV | 109(2) d | IT (97.6%) | 127Te | 11/2- | ||||
| β- (2.4%) | 127I | ||||||||
| 128TePrimordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma... |
52 | 76 | 127.9044631(19) | 2.2(3)×1024 aLongest measured half-life of any nuclide | β-β- | 128Xe | 0+ | 0.3174(8) | |
| 128mTe | 2790.7(4) keV | 370(30) ns | 10+ | ||||||
| 129Te | 52 | 77 | 128.9065982(19) | 69.6(3) min | β- | 129I | 3/2+ | ||
| 129mTe | 105.50(5) keV | 33.6(1) d | 11/2- | ||||||
| 130Te | 52 | 78 | 129.9062244(21) | 790(100)×1018 a | β-β- | 130Xe | 0+ | 0.3408(62) | |
| 130m1Te | 2146.41(4) keV | 115(8) ns | (7)- | ||||||
| 130m2Te | 2661(7) keV | 1.90(8) µs | (10+) | ||||||
| 130m3Te | 4375.4(18) keV | 261(33) ns | |||||||
| 131Te | 52 | 79 | 130.9085239(21) | 25.0(1) min | β- | 131I | 3/2+ | ||
| 131mTe | 182.250(20) keV | 30(2) h | β- (77.8%) | 131I | 11/2- | ||||
| IT (22.2%) | 131Te | ||||||||
| 132Te | 52 | 80 | 131.908553(7) | 3.204(13) d | β- | 132I | 0+ | ||
| 133Te | 52 | 81 | 132.910955(26) | 12.5(3) min | β- | 133I | (3/2+) | ||
| 133mTe | 334.26(4) keV | 55.4(4) min | β- (82.5%) | 133I | (11/2-) | ||||
| IT (17.5%) | 133Te | ||||||||
| 134Te | 52 | 82 | 133.911369(11) | 41.8(8) min | β- | 134I | 0+ | ||
| 134mTe | 1691.34(16) keV | 164.1(9) ns | 6+ | ||||||
| 135TeVery short-lived fission product Fission product Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The... , responsible for the iodine pit Iodine pit Iodine pit, also called iodine hole and xenon pit, is a temporary disabling of a nuclear reactor due to buildup of short-lived nuclear poisons in the core of a nuclear reactor. The main isotope responsible is xenon-135, mainly produced by natural decay of iodine-135. Iodine-135 is a weak neutron... as precursor of 135Xe Xenon-135 Xenon-135 is an unstable isotope of xenon with a half-life of about 9.2 hours. 135Xe is a fission product of uranium and Xe-135 is the most powerful known neutron-absorbing nuclear poison , with a significant effect on nuclear reactor operation... via 135I |
52 | 83 | 134.91645(10) | 19.0(2) s | β- | 135I | (7/2-) | ||
| 135mTe | 1554.88(17) keV | 510(20) ns | (19/2-) | ||||||
| 136Te | 52 | 84 | 135.92010(5) | 17.63(8) s | β- (98.7%) | 136I | 0+ | ||
| β-, n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (1.3%) |
135I | ||||||||
| 137Te | 52 | 85 | 136.92532(13) | 2.49(5) s | β- (97.01%) | 137I | 3/2-# | ||
| β-, n (2.99%) | 136I | ||||||||
| 138Te | 52 | 86 | 137.92922(22)# | 1.4(4) s | β- (93.7%) | 138I | 0+ | ||
| β-, n (6.3%) | 137I | ||||||||
| 139Te | 52 | 87 | 138.93473(43)# | 500 ms [>300 ns]# |
β- | 139I | 5/2-# | ||
| β-, n | 138I | ||||||||
| 140Te | 52 | 88 | 139.93885(32)# | 300ms [>300 ns]# |
β- | 140I | 0+ | ||
| β-, n | 139I | ||||||||
| 141Te | 52 | 89 | 140.94465(43)# | 100ms [>300 ns]# |
β- | 141I | 5/2-# | ||
| β-, n | 140I | ||||||||
| 142Te | 52 | 90 | 141.94908(64)# | 50 ms [>300 ns]# |
β- | 142I | 0+ | ||
See also
- Tellurium-124