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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.

Naturally Occurring Isotopes

Astatine has no naturally occurring isotopes.

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