Isotopes of Fermium (Z=100)

Click on an isotope to get more information about its decay
Isotope Half-life Spin Parity Decay Mode(s) or Abundance
242Fm 0.8 ms 0+ %SF=100
243Fm 0.18 s %A < 100, %SF < 0.5, %EC=?
244Fm 3.3 ms 0+ %SF=100
245Fm 4.2 s %A=100, %SF < 0.11
246Fm 1.1 s 0+ %A=92 3, %SF=7.3 24, %EC<1 sys
247Fm 35 s %A > 50, %EC+%B+ < 50
247m1Fm 9.2 s %A < 100
248Fm 36 s0+ %A=93 7, %EC ~ 7, %SF=0.10 5
249Fm 2.6 m (7/2+) %EC ~ 85 sys %A ~ 15 sys
250Fm 30 m 0+ %A>90, %EC<10, %SF=0.0069 12
250m1Fm 1.8 s %IT>80, %SF < 8E-5
251Fm 5.30 h(9/2-) %EC=98.20 13, %A=1.80 13
252Fm 25.39 h 0+ %A=99.9977 2, %SF=0.00232 15
253Fm 3.00 d1/2+ %EC=88 1, %A=12 1
254Fm 3.240 h 0+ %A=99.9408 2, %SF=0.0592 3
255Fm 20.07 h 7/2+ %A=100, %SF=2.3E-5 14
256Fm 157.6 m 0+ %SF=91.9 3, %A=8.1 3
257Fm 100.5 d(9/2+) %A=99.790 5, %SF=0.210 5
258Fm 370 us0+ %SF=100
259Fm 1.5 s %SF=100