General | |
---|---|
Symbol | 209Bi |
Names | bismuth-209, 209Bi, Bi-209 |
Protons (Z) | 83 |
Neutrons (N) | 126 |
Nuclide data | |
Natural abundance | 100% |
Half-life (t1/2) | 2.01×1019 years [1] |
Isotope mass | 208.9803986 Da |
Spin | 9/2− |
Excess energy | −18258.461±2.4 keV |
Binding energy | 7847.987±1.7 keV |
Parent isotopes |
209Pb (
β−) 209Po ( β+) 213At ( α) |
Decay products | 205Tl |
Decay modes | |
Decay mode | Decay energy ( MeV) |
Alpha emission | 3.1373 |
Isotopes of bismuth Complete table of nuclides |
Bismuth-209 (209Bi) is an isotope of bismuth; with the longest known half-life of any radioisotope that undergoes α-decay ( alpha decay). It has 83 protons and a magic number [2] of 126 neutrons, [2] and an atomic mass of 208.9803987 amu (atomic mass units). Primordial bismuth consists entirely of this isotope.
Bismuth-209 was long thought to have the heaviest stable nucleus of any element, but in 2003, a research team at the Institut d’Astrophysique Spatiale in Orsay, France, discovered that 209Bi undergoes alpha decay with a half-life of ≈19 exayears (1.9×1019, or 19 quintillion years), [3] [4] over 109 times longer than the estimated age of the universe. [5] The heaviest nucleus considered to be stable is now lead-208 and the heaviest stable monoisotopic element is gold ( gold-197).
Theory had previously predicted a half-life of 4.6×1019 years. It had been suspected to be radioactive for a long time. [6] The decay produces a 3.14 MeV alpha particle plus thallium-205. [3] [4]
Bismuth-209 forms 205Tl:
If perturbed, it would join in lead-bismuth neutron capture cycle from lead-206/207/208 to bismuth-209, despite low capture cross sections. Even thallium-205, the decay product of bismuth-209, reverts to lead when fully ionized. [8]
Due to its hugely long half-life, for nearly all applications 209Bi can be treated as non-radioactive. It is much less radioactive than human flesh, so it poses no real radiation hazard. Though 209Bi holds the half-life record for alpha decay, it does not have the longest known half-life of any nuclide; this distinction belongs to tellurium-128 ( 128Te) with a half-life estimated at 7.7 × 1024 years by double β-decay ( double beta decay). [9] [10] [11]
The half-life of 209Bi was confirmed in 2012 by an Italian team in Gran Sasso who reported (2.01±0.08)×1019 years. They also reported an even longer half-life for alpha decay of 209Bi to the first excited state of 205Tl (at 204 keV), was estimated at 1.66×1021 years. [12] Even though this value is shorter than the half-life of 128Te, both alpha decays of 209Bi hold the record of the thinnest natural line widths of any measurable physical excitation, estimated respectively at ΔΕ~5.5×10−43 eV and ΔΕ~1.3×10−44 eV in application of the uncertainty principle [13] (double beta decay would produce energy lines only in neutrinoless transitions, which has not been observed yet).
Because all primordial bismuth is bismuth-209, bismuth-209 is used for all normal applications of bismuth, such as being used as a replacement for lead, [14] [15] in cosmetics, [16] [17] in paints, [18] and in several medicines such as Pepto-Bismol. [5] [19] [20] Alloys containing bismuth-209 such as bismuth bronze have been used for thousands of years. [21]
210Po can be manufactured by bombarding 209Bi with neutrons in a nuclear reactor. [22] Only around 100 grams of 210Po are produced each year. [23] [22] 209Po and 208Po can be made through the proton bombardment of 209Bi in a cyclotron. [24] Astatine can also be produced by bombarding 209Bi with alpha particles. [25] [26] [27] Traces of 209Bi have also been used to create gold in nuclear reactors. [28] [29]
209Bi has been used as a target for the creation of several isotopes of superheavy elements such as dubnium, [30] [31] [32] [33] bohrium, [30] [34] meitnerium, [35] [36] [37] roentgenium, [38] [39] [40] and nihonium. [41] [42] [43]
In the red giant stars of the asymptotic giant branch, the s-process (slow process) is ongoing to produce bismuth-209 and polonium-210 by neutron capture as the heaviest elements to be formed, [44] and the latter quickly decays. [44] All elements heavier than it are formed in the r-process, or rapid process, which occurs during the first fifteen minutes of supernovas. [45] [44] Bismuth-209 is also created during the r-process. [44]
Some 209Bi was created radiogenically from the neptunium decay chain. [46] Neptunium-237 is an extinct radionuclide, but it can be found in traces in uranium ores because of neutron capture reactions. [46] [47] Americium-241, which is used in smoke detectors, [48] decays to neptunium-237.
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General | |
---|---|
Symbol | 209Bi |
Names | bismuth-209, 209Bi, Bi-209 |
Protons (Z) | 83 |
Neutrons (N) | 126 |
Nuclide data | |
Natural abundance | 100% |
Half-life (t1/2) | 2.01×1019 years [1] |
Isotope mass | 208.9803986 Da |
Spin | 9/2− |
Excess energy | −18258.461±2.4 keV |
Binding energy | 7847.987±1.7 keV |
Parent isotopes |
209Pb (
β−) 209Po ( β+) 213At ( α) |
Decay products | 205Tl |
Decay modes | |
Decay mode | Decay energy ( MeV) |
Alpha emission | 3.1373 |
Isotopes of bismuth Complete table of nuclides |
Bismuth-209 (209Bi) is an isotope of bismuth; with the longest known half-life of any radioisotope that undergoes α-decay ( alpha decay). It has 83 protons and a magic number [2] of 126 neutrons, [2] and an atomic mass of 208.9803987 amu (atomic mass units). Primordial bismuth consists entirely of this isotope.
Bismuth-209 was long thought to have the heaviest stable nucleus of any element, but in 2003, a research team at the Institut d’Astrophysique Spatiale in Orsay, France, discovered that 209Bi undergoes alpha decay with a half-life of ≈19 exayears (1.9×1019, or 19 quintillion years), [3] [4] over 109 times longer than the estimated age of the universe. [5] The heaviest nucleus considered to be stable is now lead-208 and the heaviest stable monoisotopic element is gold ( gold-197).
Theory had previously predicted a half-life of 4.6×1019 years. It had been suspected to be radioactive for a long time. [6] The decay produces a 3.14 MeV alpha particle plus thallium-205. [3] [4]
Bismuth-209 forms 205Tl:
If perturbed, it would join in lead-bismuth neutron capture cycle from lead-206/207/208 to bismuth-209, despite low capture cross sections. Even thallium-205, the decay product of bismuth-209, reverts to lead when fully ionized. [8]
Due to its hugely long half-life, for nearly all applications 209Bi can be treated as non-radioactive. It is much less radioactive than human flesh, so it poses no real radiation hazard. Though 209Bi holds the half-life record for alpha decay, it does not have the longest known half-life of any nuclide; this distinction belongs to tellurium-128 ( 128Te) with a half-life estimated at 7.7 × 1024 years by double β-decay ( double beta decay). [9] [10] [11]
The half-life of 209Bi was confirmed in 2012 by an Italian team in Gran Sasso who reported (2.01±0.08)×1019 years. They also reported an even longer half-life for alpha decay of 209Bi to the first excited state of 205Tl (at 204 keV), was estimated at 1.66×1021 years. [12] Even though this value is shorter than the half-life of 128Te, both alpha decays of 209Bi hold the record of the thinnest natural line widths of any measurable physical excitation, estimated respectively at ΔΕ~5.5×10−43 eV and ΔΕ~1.3×10−44 eV in application of the uncertainty principle [13] (double beta decay would produce energy lines only in neutrinoless transitions, which has not been observed yet).
Because all primordial bismuth is bismuth-209, bismuth-209 is used for all normal applications of bismuth, such as being used as a replacement for lead, [14] [15] in cosmetics, [16] [17] in paints, [18] and in several medicines such as Pepto-Bismol. [5] [19] [20] Alloys containing bismuth-209 such as bismuth bronze have been used for thousands of years. [21]
210Po can be manufactured by bombarding 209Bi with neutrons in a nuclear reactor. [22] Only around 100 grams of 210Po are produced each year. [23] [22] 209Po and 208Po can be made through the proton bombardment of 209Bi in a cyclotron. [24] Astatine can also be produced by bombarding 209Bi with alpha particles. [25] [26] [27] Traces of 209Bi have also been used to create gold in nuclear reactors. [28] [29]
209Bi has been used as a target for the creation of several isotopes of superheavy elements such as dubnium, [30] [31] [32] [33] bohrium, [30] [34] meitnerium, [35] [36] [37] roentgenium, [38] [39] [40] and nihonium. [41] [42] [43]
In the red giant stars of the asymptotic giant branch, the s-process (slow process) is ongoing to produce bismuth-209 and polonium-210 by neutron capture as the heaviest elements to be formed, [44] and the latter quickly decays. [44] All elements heavier than it are formed in the r-process, or rapid process, which occurs during the first fifteen minutes of supernovas. [45] [44] Bismuth-209 is also created during the r-process. [44]
Some 209Bi was created radiogenically from the neptunium decay chain. [46] Neptunium-237 is an extinct radionuclide, but it can be found in traces in uranium ores because of neutron capture reactions. [46] [47] Americium-241, which is used in smoke detectors, [48] decays to neptunium-237.
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cite journal}}
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link)