Английская Википедия:Isotopes of potassium
Шаблон:Short description Шаблон:Infobox potassium isotopes Potassium (Шаблон:Chem) has 26 known isotopes from Шаблон:Chem to Шаблон:Chem, with the exception of still-unknown Шаблон:Chem, as well as an unconfirmed report of Шаблон:Chem.[1] Three of those isotopes occur naturally: the two stable forms Шаблон:Chem (93.3%) and Шаблон:Chem (6.7%), and a very long-lived radioisotope [[Potassium-40|Шаблон:Chem]] (0.012%)
Naturally occurring radioactive Шаблон:Chem decays with a half-life of 1.248×109 years. 89% of those decays are to stable [[Calcium|Шаблон:Chem]] by beta decay, whilst 11% are to [[Argon|Шаблон:Chem]] 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. Шаблон:Chem 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: Шаблон:Chem has a nuclear spin of 4, while both of its decay daughters are even–even isotopes with spins of 0.
Шаблон:Chem 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.Шаблон:Citation needed Шаблон:Chem is the largest source of natural radioactivity in healthy animals and humans, greater even than [[carbon-14|Шаблон:Chem]]. In a human body of 70 kg mass, about 4,400 nuclei of Шаблон:Chem decay per second.[2]
The decay of Шаблон:Chem to Шаблон:Chem is used in potassium-argon dating of rocks. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic Шаблон:Chem 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., Шаблон:Chem) was retained.Шаблон:Citation needed Шаблон:Chem has also been extensively used as a radioactive tracer in studies of weathering.Шаблон:Citation needed
All other potassium isotopes have half-lives under a day, most under a minute. The least stable is Шаблон:Chem, a three-proton emitter discovered in 2019; its half-life was measured to be shorter than 10 picoseconds.[3][4]
Stable potassium isotopes have been used for several nutrient cycling studies since potassium is a macronutrient required for life.[5]
List of isotopes
Шаблон:Isotopes table |- | Шаблон:Chem[3][4] | style="text-align:right" | 19 | style="text-align:right" | 12 | | <10 ps | 3p | 28S | | | |- | 33K | style="text-align:right" | 19 | style="text-align:right" | 14 | 33.00756(21)# | <25 ns | p | 32Ar | 3/2+# | | |- | 34K | style="text-align:right" | 19 | style="text-align:right" | 15 | 33.99869(21)# | <40 ns | p | 33Ar | 1+# | | |- | rowspan=2|35K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 16 | rowspan=2|34.9880054(6) | rowspan=2|178(8) ms | β+ (99.63%) | 35Ar | rowspan=2|3/2+ | rowspan=2| | rowspan=2| |- | β+, p (.37%) | 34Cl |- | rowspan=3|36K | rowspan=3 style="text-align:right" | 19 | rowspan=3 style="text-align:right" | 17 | rowspan=3|35.9813020(4) | rowspan=3|341(3) ms | β+ (99.95%) | 36Ar | rowspan=3|2+ | rowspan=3| | rowspan=3| |- | β+, p (.048%) | 35Cl |- | β+, α (.0034%) | 32S |- | 37K | style="text-align:right" | 19 | style="text-align:right" | 18 | 36.97337589(10) | 1.2365(9) s | β+ | 37Ar | 3/2+ | | |- | 38K | style="text-align:right" | 19 | style="text-align:right" | 19 | 37.96908112(21) | 7.636(18) min | β+ | 38Ar | 3+ | | |- | style="text-indent:1em" | 38m1K | colspan="3" style="text-indent:2em" | 130.50(28) keV | 924.46(14) ms | β+ | 38Ar | 0+ | | |- | style="text-indent:1em" | 38m2K | colspan="3" style="text-indent:2em" | 3458.0(2) keV | 21.95(11) μs | IT | 38K | (7+) | | |- | 39K | style="text-align:right" | 19 | style="text-align:right" | 20 | 38.963706487(5) | colspan=3 align=center|Stable | 3/2+ | 0.932581(44) | |- | rowspan=3|40K[n 1][n 2] | rowspan=3 style="text-align:right" | 19 | rowspan=3 style="text-align:right" | 21 | rowspan=3|39.96399817(6) | rowspan=3|1.248(3)×109 y | β− (89.28%) | 40Ca | rowspan=3|4− | rowspan=3|1.17(1)×10−4 | rowspan=3| |- | EC (10.72%) | rowspan=2|40Ar |- |- | β+ (0.001%)[6] |- | style="text-indent:1em" | 40mK | colspan="3" style="text-indent:2em" | 1643.639(11) keV | 336(12) ns | IT | 40K | 0+ | | |- | 41K | style="text-align:right" | 19 | style="text-align:right" | 22 | 40.961825258(4) | colspan=3 align=center|Stable | 3/2+ | 0.067302(44) | |- | 42K | style="text-align:right" | 19 | style="text-align:right" | 23 | 41.96240231(11) | 12.355(7) h | β− | 42Ca | 2− | Trace[n 3] | |- | 43K | style="text-align:right" | 19 | style="text-align:right" | 24 | 42.9607347(4) | 22.3(1) h | β− | 43Ca | 3/2+ | | |- | style="text-indent:1em" | 43mK | colspan=3 style="text-indent:2em" | 738.30(6) keV | 200(5) ns | IT | 43K | 7/2− | | |- | 44K | style="text-align:right" | 19 | style="text-align:right" | 25 | 43.9615870(5) | 22.13(19) min | β− | 44Ca | 2− | | |- | 45K | style="text-align:right" | 19 | style="text-align:right" | 26 | 44.9606915(6) | 17.8(6) min | β− | 45Ca | 3/2+ | | |- | 46K | style="text-align:right" | 19 | style="text-align:right" | 27 | 45.9619816(8) | 105(10) s | β− | 46Ca | 2− | | |- | 47K | style="text-align:right" | 19 | style="text-align:right" | 28 | 46.9616616(15) | 17.50(24) s | β− | 47Ca | 1/2+ | | |- | rowspan=2|48K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 29 | rowspan=2|47.9653412(8) | rowspan=2|6.8(2) s | β− (98.86%) | 48Ca | rowspan=2|1− | rowspan=2| | rowspan=2| |- | β−, n (1.14%) | 47Ca |- | rowspan=2|49K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 30 | rowspan=2|48.9682108(9) | rowspan=2|1.26(5) s | β−, n (86%) | 48Ca | rowspan=2|(3/2+) | rowspan=2| | rowspan=2| |- | β− (14%) | 49Ca |- | rowspan=2|50K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 31 | rowspan=2|49.972380(8) | rowspan=2|472(4) ms | β− (71%) | 50Ca | rowspan=2|0− | rowspan=2| | rowspan=2| |- | β−, n (29%) | 49Ca |- | style="text-indent:1em" | 50mK | colspan=3 style="text-indent:2em" | 171.4(4) keV | 125(40) ns | IT | 50K | (2−) | | |- | rowspan=2|51K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 32 | rowspan=2|50.975828(14) | rowspan=2|365(5) ms | β−, n (65%) | 50Ca | rowspan=2|3/2+ | rowspan=2| | rowspan=2| |- | β− (35%) | 51Ca |- | rowspan=3|52K | rowspan=3 style="text-align:right" | 19 | rowspan=3 style="text-align:right" | 33 | rowspan=3|51.98160(4) | rowspan=3|110(4) ms | β−, n (74%) | 51Ca | rowspan=3|2−# | rowspan=3| | rowspan=3| |- | β− (23.7%) | 52Ca |- | β−, 2n (2.3%) | 50Ca |- | rowspan=3|53K | rowspan=3 style="text-align:right" | 19 | rowspan=3 style="text-align:right" | 34 | rowspan=3|52.98680(12) | rowspan=3|30(5) ms | β−, n (64%) | 52Ca | rowspan=3|(3/2+) | rowspan=3| | rowspan=3| |- | β− (26%) | 53Ca |- | β−, 2n (10%) | 51Ca |- | rowspan=2|54K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 35 | rowspan=2|53.99463(64)# | rowspan=2|10(5) ms | β− (>99.9%) | 54Ca | rowspan=2|2−# | rowspan=2| | rowspan=2| |- | β−, n (<.1%) | 53Ca |- | rowspan=2|55K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 36 | rowspan=2|55.00076(75)# | rowspan=2|3# ms | β− | 55Ca | rowspan=2|3/2+# | rowspan=2| | rowspan=2| |- | β−, n | 54Ca |- | rowspan=2|56K | rowspan=2 style="text-align:right" | 19 | rowspan=2 style="text-align:right" | 37 | rowspan=2|56.00851(86)# | rowspan=2|1# ms | β− | 56Ca | rowspan=2|2−# | rowspan=2| | rowspan=2| |- | β−, n | 55Ca |- | 57K[7][1] | style="text-align:right" | 19 | style="text-align:right" | 38 | | | β− | 57Ca | | | |- | 59K[1][n 4] | style="text-align:right" | 19 | style="text-align:right" | 40 | | | β− | 59Ca | | | Шаблон:Isotopes table/footer
See also
References
Шаблон:Navbox element isotopes
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