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Isotopes of the Element Mendelevium

[Click for Main Data]

Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.

Known Isotopes

Mass NumberHalf-lifeDecay ModeBranching Percentage
2450.90 millisecondsAlpha DecayNo Data Available
Spontaneous FissionNo Data Available
245m0.35 secondsElectron CaptureNo Data Available
Alpha DecayNo Data Available
2460.9 secondsAlpha Decay100.00%
Electron Capture> 77.00%
Alpha Decay< 23.00%
Spontaneous Fission (suspected)No Data Available
Electron Capture (suspected)No Data Available
2471.2 secondsAlpha Decay99.90%
Spontaneous Fission< 0.10%
247m0.25 secondsAlpha Decay79.00%
Spontaneous Fission21.00%
24813 secondsAlpha Decay58.00%
Electron Capture42.00%
24921.7 secondsAlpha Decay> 60.00%
Electron Capture<= 40.00%
249m1.9 secondsAlpha Decay (suspected)No Data Available
25025 secondsAlpha Decay7.00%
Electron Capture93.00%
2514.3 minutesElectron Capture90.00%
Alpha Decay10.00%
2522.3 minutesElectron Capture<= 100.00%
2536 minutesElectron Capture<= 100.00%
Alpha DecayNo Data Available
25428 minutesElectron Capture<= 100.00%
Electron Capture<= 100.00%
25527 minutesElectron Capture92.00%
Alpha Decay8.00%
Spontaneous Fission< 0.15%
25677 minutesElectron Capture90.80%
Alpha Decay9.20%
Spontaneous Fission< 3.00%
2575.52 hoursElectron Capture85.00%
Alpha Decay15.00%
Spontaneous Fission< 1.00%
25851.5 daysAlpha Decay100.00%
Spontaneous FissionNo Data Available
258m57.0 minutesElectron Capture>= 70.00%
Spontaneous FissionNo Data Available
25996 minutesAlpha Decay< 1.30%
Spontaneous Fission100.00%
26031.8 daysSpontaneous Fission>= 42.00%
Alpha Decay<= 25.00%
Electron Capture<= 23.00%
Beta-minus Decay<= 10.00%
261No Data AvailableAlpha Decay (suspected)No Data Available
262No Data AvailableSpontaneous Fission (suspected)No Data Available
Alpha Decay (suspected)No Data Available