Isotopes of polonium: Difference between revisions
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'''[[Polonium]]''' ('''Po''') has 33 [[isotopes]], all of which are [[radioactivity|radioactive]], with between 186 and 227 nucleons. <sup>210</sup>Po with a half-life of 138.376 days has the longest half-life of naturally occurring polonium. <sup>209</sup>Po with a half-life of 103 years has the longest half-life of all |
'''[[Polonium]]''' ('''Po''') has 33 [[isotopes]], all of which are [[radioactivity|radioactive]], with between 186 and 227 nucleons. <sup>210</sup>Po with a [[half-life]] of 138.376 days has the longest half-life of naturally occurring polonium. <sup>209</sup>Po with a half-life of 103 years has the longest half-life of all [[isotope]]s of polonium. <sup>209</sup>Po and <sup>208</sup>Po (half-life 2.9 years) can be made through the alpha, proton, or [[deuteron bombardment]] of [[lead]] or [[bismuth]] in a [[cyclotron]].{{Citation needed|date=March 2011}} |
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== Polonium-210 == |
== Polonium-210 == |
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<sup>210</sup>Po is an [[alpha decay|alpha emitter]] that has a half-life of 138.376 days; it decays directly to its [[decay product|daughter isotope]] [[lead-206|<sup>206</sup>Pb]]. A milligram of <sup>210</sup>Po emits as many alpha particles per second as 5 grams of [[Radium-226|<sup>226</sup>Ra]].<ref>http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elements.pdf</ref> A few [[curie]]s (1 curie equals 37 [[Becquerel|gigabecquerels]]) of <sup>210</sup>Po emit a blue glow which is caused by [[Excited state|excitation]] of surrounding air. A single gram of <sup>210</sup>Po generates 140 watts of power.<ref>[http://www.ead.anl.gov/pub/doc/polonium.pdf Polonium], Argonne National Laboratory</ref> Because it emits many [[alpha radiation|alpha particles]], which are stopped within a very short distance in dense media and release their energy, <sup>210</sup>Po has been used as a lightweight heat source to power [[Radioisotope thermoelectric generator|thermoelectric cells]] in [[artificial satellite]]s; for instance, <sup>210</sup>Po heat source was also used in each of the [[Lunokhod]] rovers deployed on the surface of the [[Moon]], to keep their internal components warm during the lunar nights.<ref>Andrew Wilson, ''Solar System Log'', (London: Jane's Publishing Company Ltd, 1987), p. 64.</ref> Some anti-static |
<sup>210</sup>Po is an [[alpha decay|alpha emitter]] that has a half-life of 138.376 days; it decays directly to its [[decay product|daughter isotope]] [[lead-206|<sup>206</sup>Pb]]. A milligram of <sup>210</sup>Po emits as many alpha particles per second as 5 grams of [[Radium-226|<sup>226</sup>Ra]].<ref>http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elements.pdf</ref> A few [[curie]]s (1 curie equals 37 [[Becquerel|gigabecquerels]]) of <sup>210</sup>Po emit a blue glow which is caused by [[Excited state|excitation]] of surrounding air. A single [[gram]] of <sup>210</sup>Po generates 140 watts of power.<ref>[http://www.ead.anl.gov/pub/doc/polonium.pdf Polonium], Argonne National Laboratory</ref> Because it emits many [[alpha radiation|alpha particles]], which are stopped within a very short distance in dense media and release their energy, <sup>210</sup>Po has been used as a lightweight [[heat source]] to power [[Radioisotope thermoelectric generator|thermoelectric cells]] in [[artificial satellite]]s; for instance, <sup>210</sup>Po heat source was also used in each of the [[Lunokhod]] rovers deployed on the surface of the [[Moon]], to keep their internal components warm during the lunar nights.<ref>Andrew Wilson, ''Solar System Log'', (London: Jane's Publishing Company Ltd, 1987), p. 64.</ref> Some [[anti-static brush]]es contain up to {{convert|500|µCi|MBq}} of <sup>210</sup>Po as a source of charged particles for neutralizing static electricity in materials like photographic film.<ref>[http://www.nrdstaticcontrol.com/DataSheets.html Staticmaster<!-- Bot generated title -->]</ref> <sup>210</sup>Po is also used in [[Modulated neutron initiator|initiators]] for atomic bombs through the (α,n) reaction with [[beryllium]]. |
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The majority of the time <sup>210</sup>Po decays by emission of an [[alpha particle]] only, not by emission of an alpha particle and a [[gamma ray]]. About one in 100,000 decays results in the emission of a gamma ray.<ref>[http://atom.kaeri.re.kr/cgi-bin/decay?Po-210%20A 210PO A DECAY<!-- Bot generated title -->]</ref> This low gamma ray production rate makes it more difficult to find and identify this isotope. Rather than gamma ray spectroscopy, alpha spectroscopy is the best method of measuring this isotope. |
The majority of the time <sup>210</sup>Po decays by emission of an [[alpha particle]] only, not by emission of an alpha particle and a [[gamma ray]]. About one in 100,000 decays results in the emission of a gamma ray.<ref>[http://atom.kaeri.re.kr/cgi-bin/decay?Po-210%20A 210PO A DECAY<!-- Bot generated title -->]</ref> This low gamma ray production rate makes it more difficult to find and identify this isotope. Rather than [[gamma ray spectroscopy]], [[Alpha-particle_spectroscopy|alpha spectroscopy]] is the best method of measuring this isotope. |
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<sup>210</sup>Po occurs in minute amounts in nature, where it is an intermediate isotope in the radium series (also known as the uranium series) [[decay chain]]. It is generated via beta decay from <sup>210</sup>[[Bismuth|Bi]]. |
<sup>210</sup>Po occurs in minute amounts in nature, where it is an intermediate isotope in the [[radium series]] (also known as the uranium series) [[decay chain]]. It is generated via beta decay from <sup>210</sup>[[Bismuth|Bi]]. |
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<sup>210</sup>Po is extremely toxic, with one microgram being enough to kill the average adult (250,000 times more toxic than hydrogen cyanide by weight). |
<sup>210</sup>Po is extremely toxic, with one microgram being enough to kill the average adult (250,000 times more toxic than hydrogen cyanide by weight). |
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Revision as of 16:47, 7 November 2013
Polonium (Po) has 33 isotopes, all of which are radioactive, with between 186 and 227 nucleons. 210Po with a half-life of 138.376 days has the longest half-life of naturally occurring polonium. 209Po with a half-life of 103 years has the longest half-life of all isotopes of polonium. 209Po and 208Po (half-life 2.9 years) can be made through the alpha, proton, or deuteron bombardment of lead or bismuth in a cyclotron.[citation needed]
Polonium-210
210Po is an alpha emitter that has a half-life of 138.376 days; it decays directly to its daughter isotope 206Pb. A milligram of 210Po emits as many alpha particles per second as 5 grams of 226Ra.[1] A few curies (1 curie equals 37 gigabecquerels) of 210Po emit a blue glow which is caused by excitation of surrounding air. A single gram of 210Po generates 140 watts of power.[2] Because it emits many alpha particles, which are stopped within a very short distance in dense media and release their energy, 210Po has been used as a lightweight heat source to power thermoelectric cells in artificial satellites; for instance, 210Po heat source was also used in each of the Lunokhod rovers deployed on the surface of the Moon, to keep their internal components warm during the lunar nights.[3] Some anti-static brushes contain up to 500 microcuries (19 MBq) of 210Po as a source of charged particles for neutralizing static electricity in materials like photographic film.[4] 210Po is also used in initiators for atomic bombs through the (α,n) reaction with beryllium.
The majority of the time 210Po decays by emission of an alpha particle only, not by emission of an alpha particle and a gamma ray. About one in 100,000 decays results in the emission of a gamma ray.[5] This low gamma ray production rate makes it more difficult to find and identify this isotope. Rather than gamma ray spectroscopy, alpha spectroscopy is the best method of measuring this isotope.
210Po occurs in minute amounts in nature, where it is an intermediate isotope in the radium series (also known as the uranium series) decay chain. It is generated via beta decay from 210Bi.
210Po is extremely toxic, with one microgram being enough to kill the average adult (250,000 times more toxic than hydrogen cyanide by weight). 210Po was used to kill Russian dissident and ex-FSB officer Alexander V. Litvinenko in 2006[6] and, following exhumation and analysis of his corpse, was in November 2013 suspected as a possible cause of Yasser Arafat's death.[7]
Table
| Nuclide symbol |
Historic name |
Z(p)[8][9] | N(n)[8][9] | Isotopic mass (u)[10] |
Half-life[10][11][12] | Decay mode(s)[13][n 1] |
Daughter isotope(s)[n 2] |
Nuclear spin[10][11][12] |
Representative isotopic composition (mole fraction) |
Range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|---|
| Excitation energy | ||||||||||
| 188Po | 84 | 104 | 187.999422(21) | 430(180) µs [0.40(+20-15) ms] |
0+ | |||||
| 189Po | 84 | 105 | 188.998481(24) | 5(1) ms | 3/2-# | |||||
| 190Po | 84 | 106 | 189.995101(14) | 2.46(5) ms | α (99.9%) | 186Pb | 0+ | |||
| β+ (.1%) | 190Bi | |||||||||
| 191Po | 84 | 107 | 190.994574(12) | 22(1) ms | α | 187Pb | 3/2-# | |||
| β+ (rare) | 191Bi | |||||||||
| 191mPo | 130(21) keV | 93(3) ms | (13/2+) | |||||||
| 192Po | 84 | 108 | 191.991335(13) | 32.2(3) ms | α (99%) | 188Pb | 0+ | |||
| β+ (1%) | 192Bi | |||||||||
| 192mPo | 2600(500)# keV | ~1 µs | 12+# | |||||||
| 193Po | 84 | 109 | 192.99103(4) | 420(40) ms [370(+46-40) ms] |
α | 189Pb | 3/2-# | |||
| β+ (rare) | 193Bi | |||||||||
| 193mPo | 100(30)# keV | 240(10) ms [243(+11-10) ms] |
α | 189Pb | (13/2+) | |||||
| β+ (rare) | 193Bi | |||||||||
| 194Po | 84 | 110 | 193.988186(13) | 0.392(4) s | α | 190Pb | 0+ | |||
| β+ (rare) | 194Bi | |||||||||
| 194mPo | 2525(2) keV | 15(2) µs | (11-) | |||||||
| 195Po | 84 | 111 | 194.98811(4) | 4.64(9) s | α (75%) | 191Pb | 3/2-# | |||
| β+ (25%) | 195Bi | |||||||||
| 195mPo | 110(50) keV | 1.92(2) s | α (90%) | 191Pb | 13/2+# | |||||
| β+ (10%) | 195Bi | |||||||||
| IT (.01%) | 195Po | |||||||||
| 196Po | 84 | 112 | 195.985535(14) | 5.56(12) s | α (94%) | 192Pb | 0+ | |||
| β+ (6%) | 196Bi | |||||||||
| 196mPo | 2490.5(17) keV | 850(90) ns | (11-) | |||||||
| 197Po | 84 | 113 | 196.98566(5) | 53.6(10) s | β+ (54%) | 197Bi | (3/2-) | |||
| α (44%) | 193Pb | |||||||||
| 197mPo | 230(80)# keV | 25.8(1) s | α (84%) | 193Pb | (13/2+) | |||||
| β+ (16%) | 197Bi | |||||||||
| IT (.01%) | 197Po | |||||||||
| 198Po | 84 | 114 | 197.983389(19) | 1.77(3) min | α (57%) | 194Pb | 0+ | |||
| β+ (43%) | 198Bi | |||||||||
| 198m1Po | 2565.92(20) keV | 200(20) ns | 11- | |||||||
| 198m2Po | 2691.86(20) keV | 750(50) ns | 12+ | |||||||
| 199Po | 84 | 115 | 198.983666(25) | 5.48(16) min | β+ (92.5%) | 199Bi | (3/2-) | |||
| α (7.5%) | 195Pb | |||||||||
| 199mPo | 312.0(28) keV | 4.17(4) min | β+ (73.5%) | 199Bi | 13/2+ | |||||
| α (24%) | 195Pb | |||||||||
| IT (2.5%) | 199Po | |||||||||
| 200Po | 84 | 116 | 199.981799(15) | 11.5(1) min | β+ (88.8%) | 200Bi | 0+ | |||
| α (11.1%) | 196Pb | |||||||||
| 201Po | 84 | 117 | 200.982260(6) | 15.3(2) min | β+ (98.4%) | 201Bi | 3/2- | |||
| α (1.6%) | 197Pb | |||||||||
| 201mPo | 424.1(24) keV | 8.9(2) min | IT (56%) | 201Po | 13/2+ | |||||
| EC (41%) | 201Bi | |||||||||
| α (2.9%) | 197Pb | |||||||||
| 202Po | 84 | 118 | 201.980758(16) | 44.7(5) min | β+ (98%) | 202Bi | 0+ | |||
| α (2%) | 198Pb | |||||||||
| 202mPo | 2626.7(7) keV | >200 ns | 11- | |||||||
| 203Po | 84 | 119 | 202.981420(28) | 36.7(5) min | β+ (99.89%) | 203Bi | 5/2- | |||
| α (.11%) | 199Pb | |||||||||
| 203m1Po | 641.49(17) keV | 45(2) s | IT (99.96%) | 203Po | 13/2+ | |||||
| α (.04%) | 199Pb | |||||||||
| 203m2Po | 2158.5(6) keV | >200 ns | ||||||||
| 204Po | 84 | 120 | 203.980318(12) | 3.53(2) h | β+ (99.33%) | 204Bi | 0+ | |||
| α (.66%) | 200Pb | |||||||||
| 205Po | 84 | 121 | 204.981203(21) | 1.66(2) h | β+ (99.96%) | 205Bi | 5/2- | |||
| α (.04%) | 201Pb | |||||||||
| 205m1Po | 143.166(17) keV | 310(60) ns | 1/2- | |||||||
| 205m2Po | 880.30(4) keV | 645 µs | 13/2+ | |||||||
| 205m3Po | 1461.21(21) keV | 57.4(9) ms | IT | 205Po | 19/2- | |||||
| 205m4Po | 3087.2(4) keV | 115(10) ns | 29/2- | |||||||
| 206Po | 84 | 122 | 205.980481(9) | 8.8(1) d | β+ (94.55%) | 206Bi | 0+ | |||
| α (5.45%) | 202Pb | |||||||||
| 206m1Po | 1585.85(11) keV | 222(10) ns | (8+)# | |||||||
| 206m2Po | 2262.22(14) keV | 1.05(6) µs | (9-)# | |||||||
| 207Po | 84 | 123 | 206.981593(7) | 5.80(2) h | β+ (99.97%) | 207Bi | 5/2- | |||
| α (.021%) | 203Pb | |||||||||
| 207m1Po | 68.573(14) keV | 205(10) ns | 1/2- | |||||||
| 207m2Po | 1115.073(16) keV | 49(4) µs | 13/2+ | |||||||
| 207m3Po | 1383.15(6) keV | 2.79(8) s | IT | 207Po | 19/2- | |||||
| 208Po | 84 | 124 | 207.9812457(19) | 2.898(2) a | α (99.99%) | 204Pb | 0+ | |||
| β+ (.00277%) | 208Bi | |||||||||
| 209Po | 84 | 125 | 208.9824304(20) | 102(5) a | α (99.52%) | 205Pb | 1/2- | |||
| β+ (.48%) | 209Bi | |||||||||
| 210Po | Radium F | 84 | 126 | 209.9828737(13) | 138.376(2) d | α | 206Pb | 0+ | Trace[n 3] | |
| 210mPo | 5057.61(4) keV | 263(5) ns | 16+ | |||||||
| 211Po | Actinium C' | 84 | 127 | 210.9866532(14) | 0.516(3) s | α | 207Pb | 9/2+ | Trace[n 4] | |
| 211m1Po | 1462(5) keV | 25.2(6) s | α (99.98%) | 207Pb | (25/2+) | |||||
| IT (.016%) | 211Po | |||||||||
| 211m2Po | 2135.7(9) keV | 243(21) ns | (31/2-) | |||||||
| 211m3Po | 4873.3(17) keV | 2.8(7) µs | (43/2+) | |||||||
| 212Po | Thorium C' | 84 | 128 | 211.9888680(13) | 299(2) ns | α | 208Pb | 0+ | Trace[n 5] | |
| 212mPo | 2911(12) keV | 45.1(6) s | α (99.93%) | 208Pb | (18+) | |||||
| IT (.07%) | 212Po | |||||||||
| 213Po | 84 | 129 | 212.992857(3) | 3.65(4) µs | α | 209Pb | 9/2+ | |||
| 214Po | Radium C' | 84 | 130 | 213.9952014(16) | 164.3(20) µs | α | 210Pb | 0+ | Trace[n 3] | |
| 215Po | Actinium A | 84 | 131 | 214.9994200(27) | 1.781(4) ms | α (99.99%) | 211Pb | 9/2+ | Trace[n 4] | |
| β- (2.3×10−4%) | 215At | |||||||||
| 216Po | Thorium A | 84 | 132 | 216.0019150(24) | 0.145(2) s | α | 212Pb | 0+ | Trace[n 5] | |
| β-β- (rare) | 216Rn | |||||||||
| 217Po | 84 | 133 | 217.006335(7) | 1.47(5) s | α (95%) | 213Pb | 5/2+# | |||
| β- (5%) | 217At | |||||||||
| 218Po | Radium A | 84 | 134 | 218.0089730(26) | 3.10(1) min | α (99.98%) | 214Pb | 0+ | Trace[n 3] | |
| β- (.02%) | 218At | |||||||||
| 219Po | 84 | 135 | 219.01374(39)# | 2# min [>300 ns] |
7/2+# | |||||
| 220Po | 84 | 136 | 220.01660(39)# | 40# s [>300 ns] |
0+ | |||||
- ^ Abbreviations:
EC: Electron capture
IT: Isomeric transition - ^ Bold for stable isotopes, bold italics for nearly stable isotopes (half-life longer than the age of the universe)
- ^ a b c Intermediate decay product of Uranium-238
- ^ a b Intermediate decay product of Uranium-235
- ^ a b Intermediate decay product of Thorium-232
Notes
- Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.
- Half-life abbreviations are a=annum(year), d=day, min=minute, s=second, ms=millisecond, µs=microsecond, ns=nanosecond.
- A superscripted m (or m2, etc.) refers to an isomer of that particular isotope.
References
- ^ http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elements.pdf
- ^ Polonium, Argonne National Laboratory
- ^ Andrew Wilson, Solar System Log, (London: Jane's Publishing Company Ltd, 1987), p. 64.
- ^ Staticmaster
- ^ 210PO A DECAY
- ^ Cowell, Alan (November 24, 2006). "Radiation Poisoning Killed Ex-Russian Spy". The New York Times.
- ^ "Arafat's death: what is Polonium-210?". Al Jazeera. July 10, 2012.
- ^ a b J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
{{cite journal}}: Unknown parameter|laysummary=ignored (help) - ^ a b c G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
{{cite web}}: Check date values in:|accessdate=(help) - ^ a b N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide (ed.). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. p. 11-50. ISBN 978-0-8493-0485-9.
- ^ http://www.nucleonica.net/unc.aspx
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