K
Калій
Z 19 39,098 г/мольЛужний метал
| 39K | 20 | 38,9637 | -33 807,195 | 93,2581% | Стабільний | 3/2+ | --- | 1921 |
| 41K | 22 | 40,9618 | -35 559,549 | 6,7302% | Стабільний | 3/2+ | --- | 1921 |
| 40K | 21 | 39,964 | -33 535,5 | 0,0117% | 1,25 Гр | 4- | β⁻→40Ca(89,28%) β⁺→40Ar(10,72%) | 1935 |
| 31K | 12 | 31,0368 | 34 260,0 | --- | --- | (3/2+) | p(100%) | 2019 |
| 32K | 13 | 32,0236 | 21 990,0 | --- | --- | (1+) | p→31Ar | --- |
| 32mK | 13 | 32,0246 | 22 940,0 | --- | --- | (4+) | p→31Ar | --- |
| 33K | 14 | 33,0081 | 7 540,0 | --- | --- | (3/2+) | p→32Ar | --- |
| 34K | 15 | 33,9987 | -1 220,0 | --- | --- | (1+) | p→33Ar | --- |
| 35K | 16 | 34,988 | -11 172,9 | --- | 175,2 мс | 3/2+ | β⁺→35Ar(99,63%) β⁺p→34Cl(0,37%) | 1976 |
| 36K | 17 | 35,9813 | -17 417,2 | --- | 341,0 мс | 2+ | β⁺→36Ar(99,949%) β⁺p→35Cl(0,048%) β⁺α→32S(0,003%) | 1967 |
| 37K | 18 | 36,9734 | -24 800,2 | --- | 1,24 с | 3/2+ | β⁺→37Ar(100%) | 1958 |
| 38K | 19 | 37,9691 | -28 800,76 | --- | 7,65 хв | 3+ | β⁺→38Ar(100%) | 1937 |
| 38mK | 19 | 37,9692 | -28 670,61 | --- | 924,35 мс | 0+ | β⁺→38Ar(99,967%) γ→38K(0,033%) | 1953 |
| 38nK | 19 | 37,9728 | -25 342,66 | --- | 21,95 мкс | (7+) | γ→38K(100%) | 1971 |
| 40mK | 21 | 39,9658 | -31 891,86 | --- | 336,0 нс | 0+ | γ→40K(100%) | 1968 |
| 42K | 23 | 41,9624 | -35 022,03 | --- | 12,36 год | 2- | β⁻→42Ca(100%) | 1935 |
| 43K | 24 | 42,9607 | -36 575,4 | --- | 22,3 год | 3/2+ | β⁻→43Ca(100%) | 1949 |
| 43mK | 24 | 42,9615 | -35 837,1 | --- | 200,0 нс | 7/2- | γ→43K(100%) | 1978 |
| 44K | 25 | 43,9616 | -35 781,5 | --- | 22,13 хв | 2- | β⁻→44Ca(100%) | 1954 |
| 45K | 26 | 44,9607 | -36 615,6 | --- | 17,8 хв | 3/2+ | β⁻→45Ca(100%) | 1964 |
| 46K | 27 | 45,962 | -35 413,9 | --- | 1,61 хв | 2- | β⁻→46Ca(100%) | 1965 |
| 47K | 28 | 46,9617 | -35 712,0 | --- | 17,38 с | 1/2+ | β⁻→47Ca(100%) | 1964 |
| 48K | 29 | 47,9653 | -32 284,5 | --- | 6,83 с | 1- | β⁻→48Ca(98,86%) β⁻n→47Ca(1,14%) | 1972 |
| 49K | 30 | 48,9682 | -29 611,5 | --- | 1,26 с | 1/2+ | β⁻n→48Ca(86%) β⁻→49Ca(14%) | 1972 |
| 50K | 31 | 49,9724 | -25 728,0 | --- | 472,0 мс | 0- | β⁻→50Ca(71,4%) β⁻n→49Ca(28,6%) β⁻n→48Ca | 1972 |
| 50mK | 31 | 49,9726 | -25 556,0 | --- | 125,0 нс | (2-) | γ→50K(100%) | 1999 |
| 51K | 32 | 50,9758 | -22 515,0 | --- | 365,0 мс | 3/2+ | β⁻n→50Ca(65%) β⁻→51Ca(35%) β⁻n→49Ca | 1983 |
| 52K | 33 | 51,9816 | -17 140,0 | --- | 110,0 мс | (2-) | β⁻n→51Ca(72,2%) β⁻→52Ca(25,5%) β⁻n→50Ca(2,3%) | 1983 |
| 53K | 34 | 52,9868 | -12 300,0 | --- | 30,0 мс | 3/2+ | β⁻n→52Ca(64%) β⁻→53Ca(26%) β⁻n→51Ca(10%) | 1983 |
| 54K | 35 | 53,9945 | -5 150,0 | --- | 10,0 мс | (2-) | β⁻→54Ca(100%) β⁻n→53Ca β⁻n→52Ca | 1983 |
| 55K | 36 | 55,0005 | 470,0 | --- | 10,0 мс | (3/2+) | β⁻→55Ca β⁻n→54Ca β⁻n→53Ca | 2009 |
| 56K | 37 | 56,0086 | 7 980,0 | --- | 5,0 мс | (2-) | β⁻→56Ca β⁻n→55Ca β⁻n→54Ca | 2009 |
| 57K | 38 | 57,0152 | 14 130,0 | --- | 2,0 мс | (3/2+) | β⁻→57Ca β⁻n→56Ca β⁻n→55Ca | 2018 |
| 58K | 39 | 58,0235 | 21 930,0 | --- | 2,0 мс | (2-) | β⁻→58Ca β⁻n→57Ca β⁻n→56Ca | 2019 |
| 59K | 40 | 59,0309 | 28 750,0 | --- | 1,0 мс | (3/2+) | β⁻→59Ca β⁻n→58Ca β⁻n→57Ca | 2018 |