(this element does not have any stable isotopes)
Atomic weight of the most stable isotope: 226.0254103(25) u
| Isotope | Atomic weight/u | Half-life |
| 223 | 223.0185023(27) | 11.43 d 5 |
| 224 | 224.0202120(23) | 3.6319 d 23 |
| 225 | 225.0236119(32) | 14.9 d 2 |
| 226 | 226.0254103(25) | 1600 y 7 |
| 228 | 228.0310707(26) | 5.75 y 3 |
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)
