Isotopes of astatine
List of isotopes
Abbreviations: EC: electron capture IT: isomeric transition SF:spontaneous fission Intermediate decay product of ²³⁵U Intermediate decay product of ²³⁸U

Isotopes of astatine

Section Title: List of isotopes
Table Section Text: Abbreviations: EC: electron capture IT: isomeric transition SF:spontaneous fission Intermediate decay product of ²³⁵U Intermediate decay product of ²³⁸U

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin and parity	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)

excitation energy

191At	85	106	1.7(+11−5) ms	(1/2+)

191mAt	2.1(+4−3) ms	(7/2−)

192At	85	107	192.00314(28)	11.5(0.6) ms	α (99.79%)	188Bi	3+#

β+, SF (0.21%)	(various)

192mAt	330(90)# keV	88(6) ms	α (99.79%)	188mBi	(9-, 10−)

β+, SF (0.21%)	(various)

193At	85	108	192.99984(6)	28(+5−4) ms	α	189Bi	(1/2+)

193m1At	50 keV	21(5) ms	(7/2−)

193m2At	39 keV	27(+4−5) ms	(13/2+)

194At	85	109	193.99873(20)	286(7) ms	α	190Bi	(4-, 5-)

β+ (rare)	194Po

194mAt	480(190) keV	323(7) ms	α	190Bi	(9-, 10-)

IT (rare)	194At

195At	85	110	194.996268(10)	328(20) ms	α (75%)	191Bi	(1/2+)

β+ (25%)	195Po

195mAt	34(7) keV	147(5) ms	(7/2-)

196At	85	111	195.99579(6)	253(9) ms	α (96%)	192Bi	(3+)

β+ (4.0%)	196Po

196m1At	−30(80) keV	20# ms	(10−)

196m2At	157.9(1) keV	11 µs	(5+)

197At	85	112	196.99319(5)	0.390(16) s	α (96%)	193Bi	(9/2−)

β+ (4.0%)	197Po

197mAt	52(10) keV	2.0(2) s	(1/2+)

198At	85	113	197.99284(5)	4.2(3) s	α (94%)	194Bi	(3+)

β+ (6%)	198Po

198mAt	330(90)# keV	1.0(2) s	(10−)

199At	85	114	198.99053(5)	6.92(13) s	α (89%)	195Bi	(9/2−)

β+ (11%)	199Po

200At	85	115	199.990351(26)	43.2(9) s	α (57%)	196Bi	(3+)

β+ (43%)	200Po

200m1At	112.7(30) keV	47(1) s	α (43%)	196Bi	(7+)

IT	200At

β+	200Po

200m2At	344(3) keV	3.5(2) s	(10−)

201At	85	116	200.988417(9)	85(3) s	α (71%)	197Bi	(9/2−)

β+ (29%)	201Po

202At	85	117	201.98863(3)	184(1) s	β+ (88%)	202Po	(2,3)+

α (12%)	198Bi

202m1At	190(40) keV	182(2) s	(7+)

202m2At	580(40) keV	460(50) ms	(10−)

203At	85	118	202.986942(13)	7.37(13) min	β+ (69%)	203Po	9/2−

α (31%)	199Bi

204At	85	119	203.987251(26)	9.2(2) min	β+ (96%)	204Po	7+

α (3.8%)	200Bi

204mAt	587.30(20) keV	108(10) ms	IT	204At	(10−)

205At	85	120	204.986074(16)	26.2(5) min	β+ (90%)	205Po	9/2−

α (10%)	201Bi

205mAt	2339.65(23) keV	7.76(14) µs	29/2+

206At	85	121	205.986667(22)	30.6(13) min	β+ (99.11%)	206Po	(5)+

α (0.9%)	202Bi

206mAt	807(3) keV	410(80) ns	(10)−

207At	85	122	206.985784(23)	1.80(4) h	β+ (91%)	207Po	9/2−

α (8.6%)	203Bi

208At	85	123	207.986590(28)	1.63(3) h	β+ (99.5%)	208Po	6+

α (0.55%)	204Bi

209At	85	124	208.986173(8)	5.41(5) h	β+ (96%)	209Po	9/2−

α (4.0%)	205Bi

210At	85	125	209.987148(8)	8.1(4) h	β+ (99.8%)	210Po	(5)+

α (0.18%)	206Bi

210m1At	2549.6(2) keV	482(6) µs	(15)−

210m2At	4027.7(2) keV	5.66(7) µs	(19)+

211At	85	126	210.9874963(30)	7.214(7) h	EC (58.2%)	211Po	9/2−

α (42%)	207Bi

212At	85	127	211.990745(8)	0.314(2) s	α (99.95%)	208Bi	(1−)

β+ (0.05%)	212Po

β− (2×10−6%)	212Rn

212m1At	223(7) keV	0.119(3) s	α (99%)	208Bi	(9−)

IT (1%)	212At

212m2At	4771.6(11) keV	152(5) µs	(25−)

213At	85	128	212.992937(5)	125(6) ns	α	209Bi	9/2−

214At	85	129	213.996372(5)	558(10) ns	α	210Bi	1−

214m1At	59(9) keV	265(30) ns

214m2At	231(6) keV	760(15) ns	9−

215At	85	130	214.998653(7)	0.10(2) ms	α	211Bi	9/2−	Trace

216At	85	131	216.002423(4)	0.30(3) ms	α (99.99%)	212Bi	1−

β− (.006%)	216Rn

EC (3×10−7%)	216Po

216mAt	413(5) keV	100# µs	(9−)

217At	85	132	217.004719(5)	32.3(4) ms	α (99.98%)	213Bi	9/2−

β− (.012%)	217Rn

218At	85	133	218.008694(12)	1.5(3) s	α (99.9%)	214Bi	1−#	Trace

β− (0.10%)	218Rn

219At	85	134	219.011162(4)	56(3) s	α (97%)	215Bi	(9/2-)	Trace

β− (3.0%)	219Rn

220At	85	135	220.01541(6)	3.71(4) min	β− (92%)	220Rn	3(−#)

α (8.0%)	216Bi

221At	85	136	221.01805(21)#	2.3(2) min	β−	221Rn	3/2−#

222At	85	137	222.02233(32)#	54(10) s	β−	222Rn

223At	85	138	223.02519(43)#	50(7) s	β−	223Rn	3/2−#

224At	85	139	224.02975(22)#	2.5(1.5) min	β−	224Rn

Sentence(s)

The longest-lived isotope is ²¹⁰At, which has a half-life of 8.1 hours where as ²¹⁹At has a half-life of 56 seconds.

final_sentence: The longest-lived isotope is ²¹⁰At, which has a half-life of 8.1 hours where as ²¹⁹At has a half-life of 56 seconds.