Isotopes of osmium
List of isotopes
Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes, bold italics for nearly stable isotopes (half-life longer than the age of the universe) Believed to undergo α decay to ¹⁸⁰W or β⁺β⁺ decay to ¹⁸⁴W with a half-life over 56×10¹² years primordial radionuclide Used in rhenium-osmium dating Believed to undergo α decay to ¹⁸³W Believed to undergo α decay to ¹⁸⁴W Believed to undergo α decay to ¹⁸⁵W Believed to undergo α decay to ¹⁸⁶W Believed to undergo α decay to ¹⁸⁸W or β−β− decay to ¹⁹²Pt with a half-life over 9.8×10¹² years

Isotopes of osmium

Section Title: List of isotopes
Table Section Text: Bold for isotopes with half-lives longer than the age of the universe (nearly stable) Abbreviations: EC: Electron capture IT: Isomeric transition Bold for stable isotopes, bold italics for nearly stable isotopes (half-life longer than the age of the universe) Believed to undergo α decay to ¹⁸⁰W or β⁺β⁺ decay to ¹⁸⁴W with a half-life over 56×10¹² years primordial radionuclide Used in rhenium-osmium dating Believed to undergo α decay to ¹⁸³W Believed to undergo α decay to ¹⁸⁴W Believed to undergo α decay to ¹⁸⁵W Believed to undergo α decay to ¹⁸⁶W Believed to undergo α decay to ¹⁸⁸W or β−β− decay to ¹⁹²Pt with a half-life over 9.8×10¹² years

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

161Os	76	85	0.64(6) ms	α	157W

162Os	76	86	161.98443(54)#	1.87(18) ms	α	158W	0+

163Os	76	87	162.98269(43)#	5.5(6) ms	α	159W	7/2−#

β+, p (rare)	162W

β+ (rare)	163Re

164Os	76	88	163.97804(22)	21(1) ms	α (98%)	160W	0+

β+ (2%)	164Re

165Os	76	89	164.97676(22)#	71(3) ms	α (60%)	161W	(7/2−)

β+ (40%)	165Re

166Os	76	90	165.972691(20)	216(9) ms	α (72%)	162W	0+

β+ (28%)	166Re

167Os	76	91	166.97155(8)	810(60) ms	α (67%)	163W	3/2−#

β+ (33%)	167Re

168Os	76	92	167.967804(13)	2.06(6) s	β+ (51%)	168Re	0+

α (49%)	164W

169Os	76	93	168.967019(27)	3.40(9) s	β+ (89%)	169Re	3/2−#

α (11%)	165W

170Os	76	94	169.963577(12)	7.46(23) s	β+ (91.4%)	170Re	0+

α (8.6%)	166W

171Os	76	95	170.963185(20)	8.3(2) s	β+ (98.3%)	171Re	(5/2−)

α (1.7%)	167W

172Os	76	96	171.960023(16)	19.2(5) s	β+ (98.9%)	172Re	0+

α (1.1%)	168W

173Os	76	97	172.959808(16)	22.4(9) s	β+ (99.6%)	173Re	(5/2−)

α (.4%)	169W

174Os	76	98	173.957062(12)	44(4) s	β+ (99.97%)	174Re	0+

α (.024%)	170W

175Os	76	99	174.956946(15)	1.4(1) min	β+	175Re	(5/2−)

176Os	76	100	175.95481(3)	3.6(5) min	β+	176Re	0+

177Os	76	101	176.954965(17)	3.0(2) min	β+	177Re	1/2−

178Os	76	102	177.953251(18)	5.0(4) min	β+	178Re	0+

179Os	76	103	178.953816(19)	6.5(3) min	β+	179Re	(1/2−)

180Os	76	104	179.952379(22)	21.5(4) min	β+	180Re	0+

181Os	76	105	180.95324(3)	105(3) min	β+	181Re	1/2−

181m1Os	48.9(2) keV	2.7(1) min	β+	181Re	(7/2)−

181m2Os	156.5(7) keV	316(18) ns	(9/2)+

182Os	76	106	181.952110(23)	22.10(25) h	EC	182Re	0+

183Os	76	107	182.95313(5)	13.0(5) h	β+	183Re	9/2+

183mOs	170.71(5) keV	9.9(3) h	β+ (85%)	183Re	1/2−

IT (15%)	183Os

184Os	76	108	183.9524891(14)	Observationally Stable	0+	2(1)×10−4

185Os	76	109	184.9540423(14)	93.6(5) d	EC	185Re	1/2−

185m1Os	102.3(7) keV	3.0(4) µs	(7/2−)#

185m2Os	275.7(8) keV	0.78(5) µs	(11/2+)

186Os	76	110	185.9538382(15)	2.0(11)×1015 y	α	182W	0+	0.0159(3)

187Os	76	111	186.9557505(15)	Observationally Stable	1/2−	0.0196(2)

188Os	76	112	187.9558382(15)	Observationally Stable	0+	0.1324(8)

189Os	76	113	188.9581475(16)	Observationally Stable	3/2−	0.1615(5)

189mOs	30.812(15) keV	5.81(6) h	IT	189Os	9/2−

190Os	76	114	189.9584470(16)	Observationally Stable	0+	0.2626(2)

190mOs	1705.4(2) keV	9.9(1) min	IT	190Os	(10)−

191Os	76	115	190.9609297(16)	15.4(1) d	β−	191Ir	9/2−

191mOs	74.382(3) keV	13.10(5) h	IT	191Os	3/2−

192Os	76	116	191.9614807(27)	Observationally Stable	0+	0.4078(19)

192mOs	2015.40(11) keV	5.9(1) s	IT (87%)	192Os	(10−)

β− (13%)	192Ir

193Os	76	117	192.9641516(27)	30.11(1) h	β−	193Ir	3/2−

194Os	76	118	193.9651821(28)	6.0(2) y	β−	194Ir	0+

195Os	76	119	194.96813(54)	6.5 min	β−	195Ir	3/2−#

196Os	76	120	195.96964(4)	34.9(2) min	β−	196Ir	0+

197Os	76	121	2.8(6) min

Sentence(s)

Six isotopes of osmium ¹⁸⁴Os, ¹⁸⁷Os, ¹⁸⁸Os, ¹⁸⁹Os, ¹⁹⁰Os, and ¹⁹²Os are stable.

final_sentence: Six isotopes of osmium ¹⁸⁴Os, ¹⁸⁷Os, ¹⁸⁸Os, ¹⁸⁹Os, ¹⁹⁰Os, and ¹⁹²Os are stable.