Isotopes of the Element Thallium

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

Isotopes of the Element Thallium with a Known Natural Abundance

Mass Number	Natural Abundance	Half-life

203	29.524%	Stable

205	70.476%	Stable

All Known Isotopes of the Element Thallium

Mass Number	Half-life	Decay Mode	Branching Percentage

177	18 milliseconds	Alpha Decay	73.00

		Proton Emission	27.00

177_m	0.23 milliseconds	Proton Emission	51.00

		Alpha Decay	49.00

178	≈ 60 milliseconds	Alpha Decay	No Data Available

		Electron Capture	No Data Available

179	0.23 seconds	Alpha Decay	< 100.00

		Electron Capture	No Data Available

179_m	1.5 milliseconds	Alpha Decay	<= 100.00

		Isomeric Transition	No Data Available

		Electron Capture	No Data Available

180	1.5 seconds	Electron Capture with delayed Spontaneous Fission	~ 1E-04

		Electron Capture	No Data Available

		Alpha Decay	No Data Available

181	3.2 seconds	Electron Capture	No Data Available

		Alpha Decay	No Data Available

181_m	1.4 seconds	Alpha Decay	No Data Available

182	3.1 seconds	Electron Capture	> 96.00

		Alpha Decay	< 4.00

183	6.9 seconds	Electron Capture	> 0.00

		Alpha Decay	No Data Available

183_m	60 milliseconds	Alpha Decay	~ 1.50

		Electron Capture	No Data Available

		Isomeric Transition	No Data Available

184	11 seconds	Electron Capture	97.90

		Alpha Decay	2.10

185	19.5 seconds	Electron Capture	No Data Available

185_m	1.83 seconds	Alpha Decay	No Data Available

		Isomeric Transition	No Data Available

186	27.5 seconds	Electron Capture	100.00

		Alpha Decay	~ 6.0E-3

186_m	2.9 seconds	Isomeric Transition	100.00

187	≈ 51 seconds	Electron Capture	< 100.00

		Alpha Decay	> 0.00

187_m	15.60 seconds	Electron Capture	< 99.90

		Isomeric Transition	< 99.90

		Alpha Decay	0.15

188	71 seconds	Electron Capture	100.00

		Electron Capture	100.00

188_m	41 milliseconds	Isomeric Transition	~ 100.00

		Electron Capture	No Data Available

189	2.3 minutes	Electron Capture	100.00

189_m	1.4 minutes	Electron Capture	100.00

		Isomeric Transition	< 4.00

190	2.6 minutes	Electron Capture	100.00

190_m	3.7 minutes	Electron Capture	100.00

191	No Data Available	Electron Capture	No Data Available

191_m	5.22 minutes	Electron Capture	100.00

192	9.6 minutes	Electron Capture	100.00

192_m	10.8 minutes	Electron Capture	100.00

193	21.6 minutes	Electron Capture	100.00

193_m	2.11 minutes	Isomeric Transition	<= 75.00

		Electron Capture	<= 25.00

194	33.0 minutes	Electron Capture	100.00

		Alpha Decay	< 1.0E-7

194_m	32.8 minutes	Electron Capture	100.00

195	1.16 hours	Electron Capture	100.00

195_m	3.6 seconds	Isomeric Transition	100.00

196	1.84 hours	Electron Capture	100.00

196_m	1.41 hours	Electron Capture	95.50

		Isomeric Transition	4.50

197	2.84 hours	Electron Capture	100.00

197_m	0.54 seconds	Isomeric Transition	100.00

198	5.3 hours	Electron Capture	100.00

198_m	1.87 hours	Electron Capture	54.00

		Isomeric Transition	46.00

198_m2	32.1 milliseconds	Isomeric Transition	100.00

199	7.42 hours	Electron Capture	100.00

200	26.1 hours	Electron Capture	100.00

201	72.912 hours	Electron Capture	100.00

202	12.23 days	Electron Capture	100.00

203	Stable	-	-

204	3.78 years	Beta-minus Decay	97.10

		Electron Capture	2.90

205	Stable	-	-

206	4.200 minutes	Beta-minus Decay	100.00

206_m	3.74 minutes	Isomeric Transition	100.00

207	4.77 minutes	Beta-minus Decay	100.00

207_m	1.33 seconds	Isomeric Transition	100.00

208	3.053 minutes	Beta-minus Decay	100.00

209	2.161 minutes	Beta-minus Decay	100.00

210	1.30 minutes	Beta-minus Decay	100.00

		Beta-minus Decay with delayed Neutron Emission	7.0E-3

This page is maintained by Steve Gagnon.

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