Isotopes of protactinium
List of isotopes
Abbreviations: CD: Cluster decay EC: Electron capture IT: Isomeric transition SF: Spontaneous fission Stable isotopes in bold Intermediate decay product of ²³⁵U Intermediate decay product of ²³⁸U

Isotopes of protactinium

Section Title: List of isotopes
Table Section Text: Abbreviations: CD: Cluster decay EC: Electron capture IT: Isomeric transition SF: Spontaneous fission Stable isotopes in bold Intermediate decay product of ²³⁵U Intermediate decay product of ²³⁸U

nuclide symbol	historic name	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

212Pa	91	121	212.02320(8)	8(5) ms [5.1(+61−19) ms]	7+#

213Pa	91	122	213.02111(8)	7(3) ms [5.3(+40−16) ms]	α	209Ac	9/2−#

214Pa	91	123	214.02092(8)	17(3) ms	α	210Ac

215Pa	91	124	215.01919(9)	14(2) ms	α	211Ac	9/2−#

216Pa	91	125	216.01911(8)	105(12) ms	α (80%)	212Ac

β+ (20%)	216Th

217Pa	91	126	217.01832(6)	3.48(9) ms	α	213Ac	9/2−#

217mPa	1860(7) keV	1.08(3) ms	α	213Ac	29/2+#

IT (rare)	217Pa

218Pa	91	127	218.020042(26)	0.113(1) ms	α	214Ac

219Pa	91	128	219.01988(6)	53(10) ns	α	215Ac	9/2−

β+ (5×10−9%)	219Th

220Pa	91	129	220.02188(6)	780(160) ns	α	216Ac	1−#

220m1Pa	34(26) keV	308(+250-99) ns	α	216Ac

220m2Pa	297(65) keV	69(+330-30) ns	α	216Ac

221Pa	91	130	221.02188(6)	4.9(8) µs	α	217Ac	9/2−

222Pa	91	131	222.02374(8)#	3.2(3) ms	α	218Ac

223Pa	91	132	223.02396(8)	5.1(6) ms	α	219Ac

β+ (.001%)	223Th

224Pa	91	133	224.025626(17)	844(19) ms	α (99.9%)	220Ac	5−#

β+ (.1%)	224Th

225Pa	91	134	225.02613(8)	1.7(2) s	α	221Ac	5/2−#

226Pa	91	135	226.027948(12)	1.8(2) min	α (74%)	222Ac

β+ (26%)	226Th

227Pa	91	136	227.028805(8)	38.3(3) min	α (85%)	223Ac	(5/2−)

EC (15%)	227Th

228Pa	91	137	228.031051(5)	22(1) h	β+ (98.15%)	228Th	3+

α (1.85%)	224Ac

229Pa	91	138	229.0320968(30)	1.50(5) d	EC (99.52%)	229Th	(5/2+)

α (.48%)	225Ac

229mPa	11.6(3) keV	420(30) ns	3/2−

230Pa	91	139	230.034541(4)	17.4(5) d	β+ (91.6%)	230Th	(2−)

β− (8.4%)	230U

α (.00319%)	226Ac

231Pa	Protoactinium	91	140	231.0358840(24)	3.276(11)×104 y	α	227Ac	3/2−	1.0000

CD (1.34×10−9%)	207Tl 24Ne

SF (3×10−10%)	(various)

CD (10−12%)	208Pb 23F

232Pa	91	141	232.038592(8)	1.31(2) d	β−	232U	(2−)

EC (.003%)	232Th

233Pa	91	142	233.0402473(23)	26.975(13) d	β−	233U	3/2−

234Pa	Uranium Z	91	143	234.043308(5)	6.70(5) h	β−	234U	4+	Trace

SF (3×10−10%)	(various)

234mPa	Uranium X2 Brevium	78(3) keV	1.17(3) min	β− (99.83%)	234U	(0−)	Trace

IT (.16%)	234Pa

SF (10−10%)	(various)

235Pa	91	144	235.04544(5)	24.44(11) min	β−	235U	(3/2−)

236Pa	91	145	236.04868(21)	9.1(1) min	β−	236U	1(−)

β−, SF (6×10−8%)	(various)

237Pa	91	146	237.05115(11)	8.7(2) min	β−	237U	(1/2+)

238Pa	91	147	238.05450(6)	2.27(9) min	β−	238U	(3−)#

β−, SF (2.6×10−6%)	(various)

239Pa	91	148	239.05726(21)#	1.8(5) h	β−	239U	(3/2)(−#)

240Pa	91	149	240.06098(32)#	2# min	β−	240U

Sentence(s)

Protactinium-234m is a member of the uranium series with a half-life of 1.17 minutes.

final_sentence: Protactinium-234m is a member of the uranium series with a half-life of 1.17 minutes.