칼륨 동위 원소
표

| 핵종 기호 | Z(p)> 들뜬 에너지 | N(n)> 들뜬 에너지 |   동위 원소 질량 (u)  > 들뜬 에너지 | 반감기 | 붕괴 방식 | 붕괴 생성물 | 핵 스핀 | 전형적 동위 원소 구성비 (몰 분율) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 32K | 19 | 13 | 32.02192(54)# | unknown | p | 31Ar | 1+# |  |
| 32mK | 950(100)# keV | 950(100)# keV | 950(100)# keV | unknown |  |  | 4+# |  |
| 33K | 19 | 14 | 33.00726(21)# | <25 ns | p | 32Ar | (3/2+)# |  |
| 34K | 19 | 15 | 33.99841(32)# | <25 ns | p | 33Ar | 1+# |  |
| 35K | 19 | 16 | 34.988010(21) | 178(8) ms | β+ (99.63%) | 35Ar | 3/2+ |  |
| 35K | 19 | 16 | 34.988010(21) | 178(8) ms | β+, p (.37%) | 34Cl | 3/2+ |  |
| 36K | 19 | 17 | 35.981292(8) | 342(2) ms | β+ (99.94%) | 36Ar | 2+ |  |
| 36K | 19 | 17 | 35.981292(8) | 342(2) ms | β+, p (.048%) | 35Cl | 2+ |  |
| 36K | 19 | 17 | 35.981292(8) | 342(2) ms | β+, α (.012%) | 32S | 2+ |  |
| 37K | 19 | 18 | 36.97337589(10) | 1.226(7) s | β+ | 37Ar | 3/2+ |  |
| 38K | 19 | 19 | 37.9690812(5) | 7.636(18) min | β+ | 38Ar | 3+ |  |
| 38m1K | 130.50(28) keV | 130.50(28) keV | 130.50(28) keV | 924.2(3) ms |  |  | 0+ |  |
| 38m2K | 3458.0(2) keV | 3458.0(2) keV | 3458.0(2) keV | 21.98(11) µs |  |  | (7+),(5+) |  |
| 39K | 19 | 20 | 38.96370668(20) | 안정 | 안정 | 안정 | 3/2+ | 0.932581(44) |
| 40K | 19 | 21 | 39.96399848(21) | 1.248(3)×109 year | β- (89.28%) | 40Ca | 4- | 1.17(1)×10−4 |
| 40K | 19 | 21 | 39.96399848(21) | 1.248(3)×109 year | ε (10.72%) | 40Ar | 4- | 1.17(1)×10−4 |
| 40K | 19 | 21 | 39.96399848(21) | 1.248(3)×109 year |  | 40Ar | 4- | 1.17(1)×10−4 |
β+ (0.001%): 
| 40mK | 1643.639(11) keV | 1643.639(11) keV | 1643.639(11) keV | 336(12) ns |  |  | 0+ |  |
| 41K | 19 | 22 | 40.96182576(21) | 안정 | 안정 | 안정 | 3/2+ | 0.067302(44) |
| 42K | 19 | 23 | 41.96240281(24) | 12.360(12) h | β- | 42Ca | 2- |  |
| 43K | 19 | 24 | 42.960716(10) | 22.3(1) h | β- | 43Ca | 3/2+ |  |
| 44K | 19 | 25 | 43.96156(4) | 22.13(19) min | β- | 44Ca | 2- |  |
| 45K | 19 | 26 | 44.960699(11) | 17.3(6) min | β- | 45Ca | 3/2+ |  |
| 46K | 19 | 27 | 45.961977(17) | 105(10) s | β- | 46Ca | 2(-) |  |
| 47K | 19 | 28 | 46.961678(9) | 17.50(24) s | β- | 47Ca | 1/2+ |  |
| 48K | 19 | 29 | 47.965514(26) | 6.8(2) s | β- (98.86%) | 48Ca | (2-) |  |
| 48K | 19 | 29 | 47.965514(26) | 6.8(2) s | β-, n (1.14%) | 47Ca | (2-) |  |
| 49K | 19 | 30 | 48.96745(8) | 1.26(5) s | β-, n (86%) | 48Ca | (3/2+) |  |
| 49K | 19 | 30 | 48.96745(8) | 1.26(5) s | β- (14%) | 49Ca | (3/2+) |  |
| 50K | 19 | 31 | 49.97278(30) | 472(4) ms | β- (71%) | 50Ca | (0-,1,2-) |  |
| 50K | 19 | 31 | 49.97278(30) | 472(4) ms | β-, n (29%) | 49Ca | (0-,1,2-) |  |
| 51K | 19 | 32 | 50.97638(54)# | 365(5) ms | β- (53%) | 51Ca | 3/2+# |  |
| 51K | 19 | 32 | 50.97638(54)# | 365(5) ms | β-, n (47%) | 50Ca | 3/2+# |  |
| 52K | 19 | 33 | 51.98261(75)# | 105(5) ms | β-, n (64%) | 51Ca | (2-)# |  |
| 52K | 19 | 33 | 51.98261(75)# | 105(5) ms | β-, 2n (21%) | 50Ca | (2-)# |  |
| 52K | 19 | 33 | 51.98261(75)# | 105(5) ms | β- (15%) | 52Ca | (2-)# |  |
| 53K | 19 | 34 | 52.98712(75)# | 30(5) ms | β-, n (67%) | 52Ca | (3/2+)# |  |
| 53K | 19 | 34 | 52.98712(75)# | 30(5) ms | β-, 2n (17%) | 51Ca | (3/2+)# |  |
| 53K | 19 | 34 | 52.98712(75)# | 30(5) ms | β- (16%) | 53Ca | (3/2+)# |  |
| 54K | 19 | 35 | 53.99420(97)# | 10(5) ms | β- (>99.9%) | 54Ca | 2-# |  |
| 54K | 19 | 35 | 53.99420(97)# | 10(5) ms | β-, n (<.1%) | 53Ca | 2-# |  |
| 55K | 19 | 36 | 54.99971(107)# | 3# ms | β- | 55Ca | 3/2+# |  |
| 55K | 19 | 36 | 54.99971(107)# | 3# ms | β-, n | 54Ca | 3/2+# |  |
↑   굵은 글꼴은 안정 동위 원소, 굵은 기울임꼴은 감기가 우주의 나이보다 긴 동위 원소(거의 안정적)
↑   칼륨-아르곤 연대 측정 에 사용된다.
↑  원시 방사성 핵종