(this element does not have any stable isotopes)
Atomic weight of the most stable isotope: 252.082980(54) u
| Isotope | Atomic weight/u | Half-life |
| 245 | 245.07125(22) | 1.1 m 1 |
| 246 | 246.07290(24) | 7.5 m 5 |
| 247 | 247.073622(21) | 4.55 m 26 |
| 248 | 248.075471(56) | 24 m 3 |
| 249 | 249.076411(32) | 102.2 m 6 |
| 250 | 250.07861(11) | 8.6 h 1 |
| 251 | 251.0799936(67) | 33 h 1 |
| 252 | 252.082980(54) | 471.7 d 19 |
| 253 | 253.0848257(27) | 20.47 d 3 |
| 254 | 254.0880222(45) | 275.7 d 5 |
| 255 | 255.090275(12) | 39.8 d 12 |
| 256 | 256.09360(11) | 25.4 m 24 |
| 257 | 257.09598(44) | 7.7 d 2 |
Units: y = year, d = day, h = hour, m = minute, s = second, ms = millisecond, µs = microsecond.
Numbers in italics are uncertainties with the same unit as the last digit of the half-life.
Atomic weights were obtained from NIST Database 144
The half-life of radioactive isotopes was obtained from the Nuclear Wallet Cards
The Atomic Line List does not contain any data for this element
(Atomic Line List v3.00b5)
