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.

All Known Isotopes of the Element Actinium

Mass Number	Half-life	Decay Mode	Branching Percentage

206	11 milliseconds	Alpha Decay	100.00

206_m	22 milliseconds	Alpha Decay	100.00

206_m2	33 milliseconds	Alpha Decay	100.00

207	27 milliseconds	Alpha Decay	No Data Available

208	95 milliseconds	Electron Capture	1.00

		Alpha Decay	No Data Available

208_m	25 milliseconds	Isomeric Transition	< 10.00

		Electron Capture	1.00

		Alpha Decay	No Data Available

209	0.10 seconds	Alpha Decay	~ 99.00

		Electron Capture	~ 1.00

210	0.35 seconds	Alpha Decay	~ 96.00

		Electron Capture	~ 4.00

211	0.25 seconds	Alpha Decay	100.00

212	0.93 seconds	Alpha Decay	~ 97.00

		Electron Capture	~ 3.00

213	0.80 seconds	Alpha Decay	<= 100.00

214	8.2 seconds	Alpha Decay	>= 89.00

		Electron Capture	<= 11.00

215	0.17 seconds	Alpha Decay	99.91

		Electron Capture	0.09

216	≈ 0.33 milliseconds	Alpha Decay	100.00

217	69 nanoseconds	Alpha Decay	100.00

		Electron Capture	<= 2.00

218	1.08 microseconds	Alpha Decay	100.00

219	11.8 microseconds	Alpha Decay	100.00

220	26.4 milliseconds	Alpha Decay	100.00

		Electron Capture	5.0E-4

221	52 milliseconds	Alpha Decay	100.00

222	5.0 seconds	Alpha Decay	99.00

		Electron Capture	1.00

222_m	63 seconds	Alpha Decay	>= 88.00

		Isomeric Transition	<= 10.00

		Electron Capture	>= 0.70

223	2.10 minutes	Alpha Decay	99.00

		Electron Capture	1.00

224	2.78 hours	Electron Capture	90.90

		Alpha Decay	9.10

		Beta-minus Decay	< 1.60

225	10.0 days	Alpha Decay	100.00

		Emission of a carbon-14 nucleus	6E-10

226	29.37 hours	Beta-minus Decay	83.00

		Electron Capture	17.00

		Alpha Decay	6.0E-3

227	21.772 years	Beta-minus Decay	98.62

		Alpha Decay	1.38

228	6.15 hours	Beta-minus Decay	100.00

229	62.7 minutes	Beta-minus Decay	100.00

230	122 seconds	Beta-minus Decay	100.00

231	7.5 minutes	Beta-minus Decay	100.00

232	119 seconds	Beta-minus Decay	100.00

233	145 seconds	Beta-minus Decay	100.00

234	44 seconds	Beta-minus Decay	100.00

235	≈ 40 seconds	Beta-minus Decay	No Data Available

236	≈ 2 minutes	Beta-minus Decay	No Data Available

This page is maintained by Steve Gagnon.

Citation and linking information

Isotopes of the Element Actinium[Click for Main Data]

Isotopes of the Element Actinium
[Click for Main Data]