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The Periodic Table of Elements

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Thorium

Isotopes of the Element Actinium

[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
20622 millisecondsAlpha Decay100.00%
206m33 millisecondsAlpha Decay100.00%
20727 millisecondsAlpha Decay100.00%
20895 millisecondsAlpha Decay~ 99.00%
Electron Capture~ 1.00%
208m25 millisecondsElectron Capture~ 10.00%
Alpha Decay~ 90.00%
2090.10 secondsAlpha Decay~ 99.00%
Electron Capture~ 1.00%
2100.35 secondsAlpha Decay91.00%
Electron Capture~ 9.00%
2110.21 secondsAlpha Decay100.00%
2120.93 secondsAlpha Decay~ 57.00%
Electron Capture~ 43.00%
213738 millisecondsAlpha Decay<= 100.00%
2148.2 secondsElectron Capture<= 11.00%
Alpha Decay>= 89.00%
2150.17 secondsAlpha Decay99.91%
Electron Capture0.09%
216440 microsecondsAlpha Decay100.00%
216m441 microsecondsAlpha Decay100.00%
21769 nanosecondsAlpha Decay100.00%
Electron Capture<= 2.00%
2181.08 microsecondsAlpha Decay100.00%
21911.8 microsecondsAlpha Decay100.00%
22026.4 millisecondsAlpha Decay100.00%
Electron Capture5.0×10-4 %
22152 millisecondsAlpha Decay100.00%
2225.0 secondsAlpha Decay99.00%
Electron Capture1.00%
222m63 secondsAlpha Decay>= 88.00%
Isomeric Transition<= 10.00%
Electron Capture>= 0.70%
2232.10 minutesAlpha Decay99.00%
Electron Capture1.00%
2242.78 hoursElectron Capture90.90%
Alpha Decay9.10%
Beta-minus Decay< 1.60%
22510.0 daysAlpha Decay100.00%
Emission of a carbon-14 nucleus4×10-12 %
22629.37 hoursBeta-minus Decay83.00%
Electron Capture17.00%
Alpha Decay6.0×10-3 %
22721.772 yearsBeta-minus Decay98.62%
Alpha Decay1.38%
2286.15 hoursBeta-minus Decay100.00%
22962.7 minutesBeta-minus Decay100.00%
230122 secondsSpontaneous Fission1.2×10-6 %
Beta-minus Decay100.00%
2317.5 minutesBeta-minus Decay100.00%
232119 secondsBeta-minus Decay100.00%
233145 secondsBeta-minus Decay100.00%
23444 secondsBeta-minus Decay100.00%
23560 secondsBeta-minus Decay100.00%
236No Data AvailableBeta-minus Decay (suspected)No Data Available
237No Data AvailableNo Data AvailableNo Data Available