Potassium ( 19K) has 26 known isotopes from 31 K to 57 K, with the exception of still-unknown 32 K, as well as an unconfirmed report of 59 K.[3] Three of those isotopes occur naturally: the two stable forms 39 K (93.3%) and 41 K (6.7%), and a very long-lived radioisotope 40 K (0.012%)
Naturally occurring radioactive 40 K decays with a half-life of 1.248×109 years. 89% of those decays are to stable 40 Ca by beta decay, whilst 11% are to 40 Ar by either electron capture or positron emission. This latter decay branch has produced an isotopic abundance of argon on Earth which differs greatly from that seen in gas giants and stellar spectra. 40 K has the longest known half-life for any positron-emitter nuclide. The long half-life of this primordial radioisotope is caused by a highly spin-forbidden transition: 40 K has a nuclear spin of 4, while both of its decay daughters are even–even isotopes with spins of 0.
40 K occurs in natural potassium in sufficient quantity that large bags of potassium chloride commercial salt substitutes can be used as a radioactive source for classroom demonstrations.[citation needed]40 K is the largest source of natural radioactivity in healthy animals and humans, greater even than 14 C. In a human body of 70 kg mass, about 4,400 nuclei of 40 K decay per second.[4]
The decay of 40 K to 40 Ar is used in potassium-argon dating of rocks. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic 40 Ar that has accumulated. Typically, the method assumes that the rocks contained no argon at the time of formation and all subsequent radiogenic argon (i.e., 40 Ar) was retained.[citation needed]40 K has also been extensively used as a radioactive tracer in studies of weathering.[citation needed]
All other potassium isotopes have half-lives under a day, most under a minute. The least stable is 31 K, a three-proton emitter discovered in 2019; its half-life was measured to be shorter than 10 picoseconds.[5][6]
^( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^ abc# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^Bold symbol as daughter – Daughter product is stable.
^( ) spin value – Indicates spin with weak assignment arguments.
^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.
^ abcTarasov, O.B. (2017). "Production of very neutron rich isotopes: What should we know?".
^ ab"A peculiar atom shakes up assumptions of nuclear structure". Nature. 573 (7773): 167. 6 September 2019. Bibcode:2019Natur.573T.167.. doi:10.1038/d41586-019-02655-9. PMID 31506620.
^ abKostyleva, D.; et al. (2019). "Towards the Limits of Existence of Nuclear Structure: Observation and First Spectroscopy of the Isotope 31K by Measuring Its Three-Proton Decay". Physical Review Letters. 123 (9): 092502. arXiv:1905.08154. Bibcode:2019PhRvL.123i2502K. doi:10.1103/PhysRevLett.123.092502. PMID 31524489. S2CID 159041565.
^"Soil potassium isotope composition during four million years of ecosystem development in Hawai'i". par.nsf.gov. June 2022.
^Half-life, decay mode, nuclear spin, and isotopic composition is sourced in: Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
^Wang, M.; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, X. (2017). "The AME2016 atomic mass evaluation (II). Tables, graphs, and references" (PDF). Chinese Physics C. 41 (3): 030003-1–030003-442. doi:10.1088/1674-1137/41/3/030003.
^Engelkemeir, D. W.; Flynn, K. F.; Glendenin, L. E. (1962). "Positron Emission in the Decay of K40". Physical Review. 126 (5): 1818. Bibcode:1962PhRv..126.1818E. doi:10.1103/PhysRev.126.1818.
^Neufcourt, L.; Cao, Y.; Nazarewicz, W.; Olsen, E.; Viens, F. (2019). "Neutron drip line in the Ca region from Bayesian model averaging". Physical Review Letters. 122 (6): 062502–1–062502–6. arXiv:1901.07632. Bibcode:2019PhRvL.122f2502N. doi:10.1103/PhysRevLett.122.062502. PMID 30822058. S2CID 73508148.
January 01, 1970
isotopes, potassium, potassium, known, isotopes, from, with, exception, still, unknown, well, unconfirmed, report, three, those, isotopes, occur, naturally, stable, forms, very, long, lived, radioisotope, main, isotopes, decay, abun, dance, half, life, mode, d. Potassium 19 K has 26 known isotopes from 31 K to 57 K with the exception of still unknown 32 K as well as an unconfirmed report of 59 K 3 Three of those isotopes occur naturally the two stable forms 39 K 93 3 and 41 K 6 7 and a very long lived radioisotope 40 K 0 012 Isotopes of potassium 19K Main isotopes Decay abun dance half life t1 2 mode pro duct 39K 93 3 stable 40K 0 0120 1 248 109 y b 40Ca e 40Ar b 40Ar 41K 6 73 stableStandard atomic weight Ar K 39 0983 0 0001 1 39 098 0 001 abridged 2 viewtalkedit Naturally occurring radioactive 40 K decays with a half life of 1 248 109 years 89 of those decays are to stable 40 Ca by beta decay whilst 11 are to 40 Ar by either electron capture or positron emission This latter decay branch has produced an isotopic abundance of argon on Earth which differs greatly from that seen in gas giants and stellar spectra 40 K has the longest known half life for any positron emitter nuclide The long half life of this primordial radioisotope is caused by a highly spin forbidden transition 40 K has a nuclear spin of 4 while both of its decay daughters are even even isotopes with spins of 0 40 K occurs in natural potassium in sufficient quantity that large bags of potassium chloride commercial salt substitutes can be used as a radioactive source for classroom demonstrations citation needed 40 K is the largest source of natural radioactivity in healthy animals and humans greater even than 14 C In a human body of 70 kg mass about 4 400 nuclei of 40 K decay per second 4 The decay of 40 K to 40 Ar is used in potassium argon dating of rocks Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic 40 Ar that has accumulated Typically the method assumes that the rocks contained no argon at the time of formation and all subsequent radiogenic argon i e 40 Ar was retained citation needed 40 K has also been extensively used as a radioactive tracer in studies of weathering citation needed All other potassium isotopes have half lives under a day most under a minute The least stable is 31 K a three proton emitter discovered in 2019 its half life was measured to be shorter than 10 picoseconds 5 6 Stable potassium isotopes have been used for several nutrient cycling studies since potassium is a macronutrient required for life 7 List of isotopes editNuclide 8 n 1 Z N Isotopic mass Da 9 n 2 n 3 Half life n 4 Decaymode Daughterisotope n 5 Spin andparity n 6 n 4 Natural abundance mole fraction Excitation energy n 4 Normal proportion Range of variation 31 K 5 6 19 12 lt 10 ps 3p 28S 33K 19 14 33 00756 21 lt 25 ns p 32Ar 3 2 34K 19 15 33 99869 21 lt 40 ns p 33Ar 1 35K 19 16 34 9880054 6 178 8 ms b 99 63 35Ar 3 2 b p 37 34Cl 36K 19 17 35 9813020 4 341 3 ms b 99 95 36Ar 2 b p 048 35Cl b a 0034 32S 37K 19 18 36 97337589 10 1 2365 9 s b 37Ar 3 2 38K 19 19 37 96908112 21 7 636 18 min b 38Ar 3 38m1K 130 50 28 keV 924 46 14 ms b 38Ar 0 38m2K 3458 0 2 keV 21 95 11 ms IT 38K 7 39K 19 20 38 963706487 5 Stable 3 2 0 932581 44 40K n 7 n 8 19 21 39 96399817 6 1 248 3 109 y b 89 28 40Ca 4 1 17 1 10 4 EC 10 72 40Ar b 0 001 10 40mK 1643 639 11 keV 336 12 ns IT 40K 0 41K 19 22 40 961825258 4 Stable 3 2 0 067302 44 42K 19 23 41 96240231 11 12 355 7 h b 42Ca 2 Trace n 9 43K 19 24 42 9607347 4 22 3 1 h b 43Ca 3 2 43mK 738 30 6 keV 200 5 ns IT 43K 7 2 44K 19 25 43 9615870 5 22 13 19 min b 44Ca 2 45K 19 26 44 9606915 6 17 8 6 min b 45Ca 3 2 46K 19 27 45 9619816 8 105 10 s b 46Ca 2 47K 19 28 46 9616616 15 17 50 24 s b 47Ca 1 2 48K 19 29 47 9653412 8 6 8 2 s b 98 86 48Ca 1 b n 1 14 47Ca 49K 19 30 48 9682108 9 1 26 5 s b n 86 48Ca 3 2 b 14 49Ca 50K 19 31 49 972380 8 472 4 ms b 71 50Ca 0 b n 29 49Ca 50mK 171 4 4 keV 125 40 ns IT 50K 2 51K 19 32 50 975828 14 365 5 ms b n 65 50Ca 3 2 b 35 51Ca 52K 19 33 51 98160 4 110 4 ms b n 74 51Ca 2 b 23 7 52Ca b 2n 2 3 50Ca 53K 19 34 52 98680 12 30 5 ms b n 64 52Ca 3 2 b 26 53Ca b 2n 10 51Ca 54K 19 35 53 99463 64 10 5 ms b gt 99 9 54Ca 2 b n lt 1 53Ca 55K 19 36 55 00076 75 3 ms b 55Ca 3 2 b n 54Ca 56K 19 37 56 00851 86 1 ms b 56Ca 2 b n 55Ca 57K 11 3 19 38 b 57Ca 59K 3 n 10 19 40 b 59Ca This table header amp footer view mK Excited nuclear isomer Uncertainty 1s is given in concise form in parentheses after the corresponding last digits Atomic mass marked value and uncertainty derived not from purely experimental data but at least partly from trends from the Mass Surface TMS a b c Values marked are not purely derived from experimental data but at least partly from trends of neighboring nuclides TNN Bold symbol as daughter Daughter product is stable spin value Indicates spin with weak assignment arguments Used in potassium argon dating Primordial radionuclide Decay product of 42Ar Discovery of this isotope is unconfirmedSee also editBanana equivalent doseReferences edit Standard Atomic Weights Potassium CIAAW 1979 Prohaska Thomas Irrgeher Johanna Benefield Jacqueline Bohlke John K Chesson Lesley A Coplen Tyler B Ding Tiping Dunn Philip J H Groning 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 a b c Tarasov O B 2017 Production of very neutron rich isotopes What should we know Radioactive Human Body Retrieved 2011 05 18 a b A peculiar atom shakes up assumptions of nuclear structure Nature 573 7773 167 6 September 2019 Bibcode 2019Natur 573T 167 doi 10 1038 d41586 019 02655 9 PMID 31506620 a b Kostyleva D et al 2019 Towards the Limits of Existence of Nuclear Structure Observation and First Spectroscopy of the Isotope 31K by Measuring Its Three Proton Decay Physical Review Letters 123 9 092502 arXiv 1905 08154 Bibcode 2019PhRvL 123i2502K doi 10 1103 PhysRevLett 123 092502 PMID 31524489 S2CID 159041565 Soil potassium isotope composition during four million years of ecosystem development in Hawai i par nsf gov June 2022 Half life decay mode nuclear spin and isotopic composition is sourced in Audi G Kondev F G Wang M Huang W J Naimi S 2017 The NUBASE2016 evaluation of nuclear properties PDF Chinese Physics C 41 3 030001 Bibcode 2017ChPhC 41c0001A doi 10 1088 1674 1137 41 3 030001 Wang M Audi G Kondev F G Huang W J Naimi S Xu X 2017 The AME2016 atomic mass evaluation II Tables graphs and references PDF Chinese Physics C 41 3 030003 1 030003 442 doi 10 1088 1674 1137 41 3 030003 Engelkemeir D W Flynn K F Glendenin L E 1962 Positron Emission in the Decay of K40 Physical Review 126 5 1818 Bibcode 1962PhRv 126 1818E doi 10 1103 PhysRev 126 1818 Neufcourt L Cao Y Nazarewicz W Olsen E Viens F 2019 Neutron drip line in the Ca region from Bayesian model averaging Physical Review Letters 122 6 062502 1 062502 6 arXiv 1901 07632 Bibcode 2019PhRvL 122f2502N doi 10 1103 PhysRevLett 122 062502 PMID 30822058 S2CID 73508148 Retrieved from https en wikipedia org w index php title Isotopes of potassium amp oldid 1195622799 Potassium 52, wikipedia, wiki, book, books, library,
