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Isotopes of the Element Astatine

[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
1911.7 millisecondsAlpha Decay100.00%
191m2.1 millisecondsAlpha Decay100.00%
19211.5 millisecondsAlpha Decay100.00%
192m88 millisecondsAlpha Decay100.00%
19328 millisecondsAlpha Decay100.00%
193m21 millisecondsAlpha Decay100.00%
193m127 millisecondsAlpha Decay24.00%
Isomeric Transition76.00%
194310 millisecondsAlpha DecayNo Data Available
194m253 millisecondsAlpha DecayNo Data Available
195328 millisecondsAlpha Decay100.00%
195m147 millisecondsAlpha Decay100.00%
1960.388 secondsAlpha Decay~ 95.10%
Electron Capture~ 4.90%
1970.388 secondsAlpha Decay96.10%
Electron Capture3.90%
197m2.0 secondsElectron CaptureNo Data Available
Isomeric Transition<= 4.0×10-3 %
Alpha Decay<= 100.00%
1983.8 secondsAlpha Decay90.00%
Electron Capture10.00%
198m1.04 secondsAlpha Decay84.00%
Electron Capture16.00%
1997.03 secondsAlpha Decay90.00%
Electron Capture10.00%
20043 secondsAlpha Decay52.00%
Electron Capture48.00%
200m47 secondsAlpha Decay43.00%
Electron Capture<= 57.00%
200m17.3 secondsElectron Capture< 89.50%
Isomeric Transition< 89.50%
Alpha Decay~ 10.50%
20185.2 secondsAlpha Decay71.00%
Electron Capture29.00%
202184 secondsElectron Capture63.00%
Alpha Decay37.00%
202m182 secondsElectron Capture91.30%
Alpha Decay8.70%
202m10.46 secondsAlpha Decay0.10%
Isomeric Transition99.90%
2037.4 minutesElectron Capture69.00%
Alpha Decay31.00%
2049.12 minutesElectron Capture96.09%
Alpha Decay3.91%
204m108 millisecondsIsomeric Transition100.00%
20526.9 minutesElectron Capture90.00%
Alpha Decay10.00%
20630.6 minutesElectron Capture99.10%
Alpha Decay0.90%
2071.81 hoursElectron Capture91.40%
Alpha Decay8.60%
2081.63 hoursElectron Capture99.45%
Alpha Decay0.55%
2095.41 hoursElectron Capture95.90%
Alpha Decay4.10%
2108.1 hoursElectron Capture99.82%
Alpha Decay0.18%
2117.214 hoursElectron Capture58.20%
Alpha Decay41.80%
2120.314 secondsElectron Capture< 0.03%
Beta-minus Decay< 2.0×10-6 %
Alpha Decay100.00%
212m0.119 secondsAlpha Decay> 99.00%
Isomeric Transition< 1.00%
213125 nanosecondsAlpha Decay100.00%
214558 nanosecondsAlpha Decay100.00%
2150.10 millisecondsAlpha Decay100.00%
2160.30 millisecondsAlpha Decay100.00%
Beta-minus Decay< 6.0×10-3 %
Electron Capture< 3.0×10-7 %
21732.3 millisecondsBeta-minus Decay7.0×10-3 %
Alpha Decay99.99%
2181.5 secondsAlpha Decay99.90%
Beta-minus Decay0.10%
21956 secondsAlpha Decay~ 97.00%
Beta-minus Decay~ 3.00%
2203.71 minutesAlpha Decay8.00%
Beta-minus Decay92.00%
2212.3 minutesBeta-minus Decay100.00%
22254 secondsBeta-minus Decay100.00%
22350 secondsBeta-minus Decay100.00%
22476 secondsBeta-minus Decay (suspected)No Data Available
225> 300 nanosecondsBeta-minus DecayNo Data Available
226> 300 nanosecondsBeta-minus DecayNo Data Available
227> 300 nanosecondsBeta-minus DecayNo Data Available
228> 300 nanosecondsBeta-minus DecayNo Data Available
229> 300 nanosecondsBeta-minus DecayNo Data Available
Beta-minus Decay with
delayed Neutron Emission
No Data Available