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Isotopes of the Element Promethium

[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.

Naturally Occurring Isotopes

Promethium has no naturally occurring isotopes.

Known Isotopes

Mass NumberHalf-lifeDecay ModeBranching Percentage
126No Data AvailableElectron Capture (suspected)No Data Available
127No Data AvailableProton Emission (suspected)No Data Available
Electron Capture (suspected)No Data Available
1281.0 secondsElectron Capture100.00%
Alpha DecayNo Data Available
Electron Capture with
delayed Proton Emission
No Data Available
1292.4 secondsElectron Capture100.00%
1302.6 secondsElectron Capture100.00%
Electron Capture with
delayed Proton Emission
No Data Available
1316.3 secondsElectron Capture100.00%
1326.2 secondsElectron Capture100.00%
Electron Capture with
delayed Proton Emission
~ 5.0×10-5 %
13313.5 secondsElectron Capture100.00%
133m< 8.8 secondsIsomeric TransitionNo Data Available
Electron CaptureNo Data Available
134≈ 5 secondsElectron Capture100.00%
134m22 secondsElectron Capture100.00%
13549 secondsElectron Capture100.00%
135m45 secondsElectron Capture100.00%
136107 secondsElectron Capture100.00%
136m47 secondsElectron Capture100.00%
1372.4 minutesElectron Capture100.00%
13810 secondsElectron Capture100.00%
138m3.24 minutesElectron CaptureNo Data Available
1394.15 minutesElectron Capture100.00%
139m180 millisecondsIsomeric Transition99.94%
Electron Capture0.06%
1409.2 secondsElectron Capture100.00%
140m5.95 minutesElectron Capture100.00%
14120.90 minutesElectron Capture100.00%
14240.5 secondsElectron Capture100.00%
142m2.0 millisecondsIsomeric Transition100.00%
143265 daysElectron Capture100.00%
144363 daysElectron Capture100.00%
14517.7 yearsElectron Capture100.00%
Alpha Decay2.8×10-7 %
1465.53 yearsElectron Capture66.00%
Beta-minus Decay34.00%
1472.6234 yearsBeta-minus Decay100.00%
1485.368 daysBeta-minus Decay100.00%
148m41.29 daysBeta-minus Decay95.80%
Isomeric Transition4.20%
14953.08 hoursBeta-minus Decay100.00%
1502.68 hoursBeta-minus Decay100.00%
15128.40 hoursBeta-minus Decay100.00%
1524.12 minutesBeta-minus Decay100.00%
152m13.8 minutesBeta-minus Decay100.00%
Isomeric Transition>= 0.00%
152m17.52 minutesBeta-minus Decay100.00%
1535.25 minutesBeta-minus Decay100.00%
1542.68 minutesBeta-minus Decay100.00%
154m1.73 minutesBeta-minus Decay100.00%
15541.5 secondsBeta-minus Decay100.00%
15626.70 secondsBeta-minus Decay100.00%
15710.56 secondsBeta-minus Decay100.00%
1584.8 secondsBeta-minus Decay100.00%
1591.5 secondsBeta-minus Decay100.00%
160No Data AvailableBeta-minus Decay (suspected)No Data Available
161No Data AvailableBeta-minus Decay (suspected)No Data Available
162No Data AvailableBeta-minus Decay (suspected)No Data Available
163No Data AvailableBeta-minus Decay (suspected)No Data Available