| Proton | Neutron | Nuclear Spin | Energy State | |
|---|---|---|---|---|
| 33K | 19 | 14 | 3/2 | |
| 34K | 19 | 15 | 1 | |
| 35K | 19 | 16 | 3/2 | |
| 36K | 19 | 17 | 2 | |
| 37K | 19 | 18 | 3/2 | |
| 38m1K | 19 | 19 | 0 | |
| 38K | 19 | 19 | 3 | |
| 38m2K | 19 | 19 | 5 | |
| 39K | 19 | 20 | 3/2 | Stable |
| 40mK | 19 | 21 | 0 | |
| 40K | 19 | 21 | -4 | |
| 41K | 19 | 22 | 3/2 | Stable |
| 42K | 19 | 23 | -2 | |
| 43K | 19 | 24 | 3/2 | |
| 44K | 19 | 25 | -2 | |
| 45K | 19 | 26 | 3/2 | |
| 46K | 19 | 27 | -2 | |
| 47K | 19 | 28 | 1/2 | |
| 48K | 19 | 29 | -2 | |
| 49K | 19 | 30 | 3/2 | |
| 51K | 19 | 32 | 3/2 | |
| 52K | 19 | 33 | -2 | |
| 53K | 19 | 34 | 3/2 | |
| 54K | 19 | 35 | -2 | |
| 55K | 19 | 36 | 3/2 |