View source for Software:Isotopes of osmium

{{Short description|Nuclides with atomic number of 76 but with different mass numbers}}
[[Chemistry:Osmium|Osmium]] (<sub>76</sub>Os) has seven naturally occurring [[Physics:Isotope|isotope]]s, five of which are stable: <sup>187</sup>Os, <sup>188</sup>Os, <sup>189</sup>Os, <sup>190</sup>Os, and (most abundant) <sup>192</sup>Os. The other natural isotopes, <sup>184</sup>Os, and <sup>186</sup>Os, have extremely long [[Physics:Half-life|half-life]] (1.12×10<sup>13</sup> years and 2×10<sup>15</sup> years, respectively) and for practical purposes can be considered to be stable as well. <sup>187</sup>Os is the daughter of <sup>187</sup>[[Chemistry:Rhenium|Re]] ([[Physics:Half-life|half-life]] 4.56×10<sup>10</sup> years) and is most often measured in an <sup>187</sup>Os/<sup>188</sup>Os ratio. This ratio, as well as the <sup>187</sup>Re/<sup>188</sup>Os ratio, have been used extensively in dating terrestrial as well as [[Astronomy:Meteorite|meteoric]] [[Earth:Rock (geology)|rock]]s. It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the [[Earth:Earth's mantle|mantle]] roots of continental [[Earth:Craton|craton]]s. However, the most notable application of Os in dating has been in conjunction with [[Chemistry:Iridium|iridium]], to analyze the layer of [[Chemistry:Shocked quartz|shocked quartz]] along the [[Earth:Cretaceous–Paleogene boundary|Cretaceous–Paleogene boundary]] that marks the extinction of the [[Biology:Dinosaur|dinosaur]]s 66 million years ago.

There are also 31 artificial radioisotopes,<ref>{{cite journal |last=Flegenheimer |first=Juan |year=2014 |title=The mystery of the disappearing isotope |journal=Revista Virtual de Química |volume=6 |number=4 |pages=1139–1142 |doi=10.5935/1984-6835.20140073 |doi-access=free }}</ref> the longest-lived of which is <sup>194</sup>Os with a half-life of six years; all others have half-lives under 93 days. There are also ten known [[Physics:Nuclear isomer|nuclear isomer]]s, the longest-lived of which is <sup>191m</sup>Os with a half-life of 13.10 hours. All isotopes and nuclear isomers of osmium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

== Uses of osmium isotopes ==
The isotopic ratio of osmium-187 and osmium-188 (<sup>187</sup>Os/<sup>188</sup>Os) can be used as a window into geochemical changes throughout the ocean's history.<ref name=":7">{{cite journal |doi=10.1046/j.1365-3121.2000.00295.x |title=The marine osmium isotope record |year=2000 |last1=Peucker-Ehrenbrink |first1=B. |last2=Ravizza |first2=G. |journal=Terra Nova |volume=12 |issue=5 |pages=205–219 |bibcode=2000TeNov..12..205P |s2cid=12486288 }}</ref> The average marine <sup>187</sup>Os/<sup>188</sup>Os ratio in oceans is 1.06.<ref name=":7"/> This value represents a balance of the continental derived riverine inputs of Os with a <sup>187</sup>Os/<sup>188</sup>Os ratio of ~1.3, and the [[Earth:Earth's mantle|mantle]]/extraterrestrial inputs with a <sup>187</sup>Os/<sup>188</sup>Os ratio of ~0.13.<ref name=":7"/> Being a descendant of <sup>187</sup>Re, <sup>187</sup>Os can be radiogenically formed by beta decay.<ref name=":4">{{cite journal |doi=10.1016/0016-7037(93)90296-9 |url=https://www.sciencedirect.com/science/article/abs/pii/0016703793902969 |title=The osmium isotopic composition of the continental crust |year=1993 |last1=Esser |first1=Bradley K. |last2=Turekian |first2=Karl K. |journal=Geochimica et Cosmochimica Acta |volume=57 |issue=13 |pages=3093–3104 |bibcode=1993GeCoA..57.3093E|doi-access=free }}</ref> This decay has actually pushed the <sup>187</sup>Os/<sup>188</sup>Os ratio of the Bulk silicate earth (Earth minus the core) by 33%.<ref name=":5">{{cite journal |url=https://www.jstor.org/stable/pdf/3558902.pdf |jstor=3558902 |title=Osmium Isotopes and Mantle Convection |last1=Hauri |first1=Erik H. |journal=Philosophical Transactions: Mathematical, Physical and Engineering Sciences |year=2002 |volume=360 |issue=1800 |pages=2371–2382 |doi=10.1098/rsta.2002.1073 |pmid=12460472 |bibcode=2002RSPTA.360.2371H |s2cid=18451805}}</ref> This is what drives the difference in the <sup>187</sup>Os/<sup>188</sup>Os ratio we see between continental materials and mantle material. [[Earth:Earth's crust|Crustal]] rocks have a much higher level of Re, which slowly degrades into <sup>187</sup>Os driving up the ratio.<ref name=":4"/> Within the mantle however, the uneven response of Re and Os results in these mantle, and melted materials being depleted in Re, and do not allow for them to accumulate <sup>187</sup>Os like the continental material.<ref name=":4"/> The input of both materials in the marine environment results in the observed <sup>187</sup>Os/<sup>188</sup>Os of the oceans and has fluctuated greatly over the history of our planet. These changes in the isotopic values of marine Os can be observed in the [[Earth:Marine sediment|marine sediment]] that is deposited, and eventually lithified in that time period.<ref name=":6">{{cite journal |doi=10.5670/oceanog.2019.133 |title=Ocean Drilling Perspectives on Meteorite Impacts |year=2019 |last1=Lowery |first1=Chistopher |last2=Morgan |first2=Joanna|last3=Gulick |first3=Sean |last4=Bralower |first4=Timothy |last5=Christeson |first5=Gail |journal=Oceanography |volume=32 |pages=120–134 |doi-access=free }}</ref> This allows for researchers to make estimates on weathering fluxes, identifying flood basalt volcanism, and impact events that may have caused some of our largest mass extinctions. The marine sediment Os isotope record has been used to identify and corroborate the impact of the K-T boundary for example.<ref name=":8">{{cite journal |doi=10.1126/science.1111081 |title=Direct Radiometric Dating of Hydrocarbon Deposits Using Rhenium-Osmium Isotopes |year=2005 |last1=Selby |first1=D. |last2=Creaser |first2=R. A. |journal=Science |volume=308 |issue=5726 |pages=1293–1295 |pmid=15919988 |bibcode=2005Sci...308.1293S |s2cid=41419594 }}</ref> The impact of this ~10&nbsp;km asteroid massively altered the <sup>187</sup>Os/<sup>188</sup>Os signature of marine sediments at that time. With the average extraterrestrial <sup>187</sup>Os/<sup>188</sup>Os of ~0.13 and the huge amount of Os this impact contributed (equivalent to 600,000 years of present-day riverine inputs) lowered the global marine <sup>187</sup>Os/<sup>188</sup>Os value of ~0.45 to ~0.2.<ref name=":7"/>

Os isotope ratios may also be used as a signal of anthropogenic impact.<ref name=":3">{{cite journal |url= |doi=10.1073/pnas.0811803106 |title=Anthropogenic osmium in rain and snow reveals global-scale atmospheric contamination |year=2009 |last1=Chen |first1=C. |last2=Sedwick |first2=P. N. |last3=Sharma |first3=M. |journal=Proceedings of the National Academy of Sciences |volume=106 |issue=19 |pages=7724–7728 |pmid=19416862 |pmc=2683094 |bibcode=2009PNAS..106.7724C |doi-access=free }}</ref> The same <sup>187</sup>Os/<sup>188</sup>Os ratios that are common in geological settings may be used to gauge the addition of anthropogenic Os through things like [[Chemistry:Catalytic converter|catalytic converter]]s.<ref name=":3"/> While catalytic converters have been shown to drastically reduce the emission of NO<sub>x</sub> and CO<sub>2</sub>, they are introducing [[Earth:Platinum group|platinum group elements]] (PGE) such as Os, to the environment.<ref name=":3"/> Other sources of anthropogenic Os include combustion of fossil fuels, smelting [[Chemistry:Chromium|chromium]] ore, and smelting of some [[Chemistry:Sulfide|sulfide]] ores. In one study, the effect of automobile exhaust on the marine Os system was evaluated. Automobile exhaust <sup>187</sup>Os/<sup>188</sup>Os has been recorded to be ~0.2 (similar to extraterrestrial and mantle derived inputs) which is heavily depleted (3, 7). The effect of anthropogenic Os can be seen best by comparing aquatic Os ratios and local sediments or deeper waters. Impacted surface waters tend to have depleted values compared to deep ocean and sediments beyond the limit of what is expected from cosmic inputs.<ref name=":3"/> This increase in effect is thought to be due to the introduction of anthropogenic airborne Os into precipitation.

The long half-life of <sup>184</sup>Os with respect to alpha decay to <sup>180</sup>W has been proposed as a [[Physics:Radiometric dating|radiometric dating]] method for osmium-rich rocks or for [[Astronomy:Planetary differentiation|differentiation of a planetary core]].<ref name="184Os"/><ref>{{cite journal |last1=Cook |first1=David L. |last2=Kruijer |first2=Thomas S. |last3=Leya |first3=Ingo |last4=Kleine |first4=Thorsten |title=Cosmogenic <sup>180</sup>W variations in meteorites and re-assessment of a possible <sup>184</sup>Os–<sup>180</sup>W decay system |journal=Geochimica et Cosmochimica Acta |date=September 2014 |volume=140 |pages=160-176 |doi=10.1016/j.gca.2014.05.013}}</ref><ref>{{cite journal |last1=Cook |first1=David L. |last2=Smith |first2=Thomas |last3=Leya |first3=Ingo |last4=Hilton |first4=Connor D. |last5=Walker |first5=Richard J. |last6=Schönbächler |first6=Maria |title=Excess <sup>180</sup>W in IIAB iron meteorites: Identification of cosmogenic, radiogenic, and nucleosynthetic components |journal=Earth Planet Sci Lett. |date=September 2018 |volume=503 |pages=29-36 |doi=10.1016/j.epsl.2018.09.021|pmc=6398611 }}</ref>

== List of isotopes ==
{{Isotopes table
|symbol=Os
|refs=NUBASE2020, AME2020 II
|notes=m, unc(), mass#, hl-nst, spin(), spin#, daughter-st, daughter-nst, p, EC, IT
}}
|-
| <sup>160</sup>Os<ref name=Os160>{{cite journal |first1=A. D. |last1=Briscoe |first2=R. D. |last2=Page |first3=J. |last3=Uusitalo |display-authors=et al. |title=Decay spectroscopy at the two-proton drip line: Radioactivity of the new nuclides <sup>160</sup>Os and <sup>156</sup>W |journal=Physics Letters B |volume=47 |date=2023 |number=138310 |doi=10.1016/j.physletb.2023.138310|doi-access=free }}</ref>
| style="text-align:right" | 76
| style="text-align:right" | 84
| 
| {{val|97|97|32|u=us}}
| [[Physics:Alpha decay|α]]
| <sup>156</sup>W
| 0+
| 
|
|-
| style="text-indent:1em" | <sup>160m</sup>Os<ref name=Os160/>
| colspan="3" style="text-indent:2em" | 1844(18)&nbsp;keV
| {{val|41|15|9|u=us}}
| α
| <sup>156</sup>W
| 8+
| 
| 
|-
| <sup>161</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 85
| 160.98905(43)#
| 0.64(6)&nbsp;ms
| α
| <sup>157</sup>W
| (7/2–)
| 
|
|-
| <sup>162</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 86
| 161.98443(32)#
| 2.1(1)&nbsp;ms
| α
| <sup>158</sup>W
| 0+
|
|
|-
| rowspan=2|<sup>163</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 87
| rowspan=2|162.98246(32)#
| rowspan=2|5.7(5)&nbsp;ms   
| α
| <sup>159</sup>W
| rowspan=2|7/2–
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> ?
| <sup>163</sup>Re
|-
| rowspan=2|<sup>164</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 88
| rowspan=2|163.97807(16)
| rowspan=2|21(1)&nbsp;ms
| α (96%)
| <sup>160</sup>W
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (4%)
| <sup>164</sup>Re
|-
| rowspan=2|<sup>165</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 89
| rowspan=2|164.97665(22)#
| rowspan=2|71(3)&nbsp;ms
| α (90%)
| <sup>161</sup>W
| rowspan=2|(7/2–)
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (10%)
| <sup>165</sup>Re
|-
| rowspan=2|<sup>166</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 90
| rowspan=2|165.972698(19)
| rowspan=2|213(5)&nbsp;ms
| α (83%)
| <sup>162</sup>W
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (17%)
| <sup>166</sup>Re
|-
| rowspan=2|<sup>167</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 91
| rowspan=2|166.971552(87)
| rowspan=2|839(5)&nbsp;ms      
| α (51%)
| <sup>163</sup>W
| rowspan=2|7/2–
| rowspan=2|
| rowspan=2|
|-
| β<sup>+</sup> (49%)
| <sup>167</sup>Re
|-
| style="text-indent:1em" | <sup>167m</sup>Os
| colspan="3" style="text-indent:2em" | 434.3(11)&nbsp;keV
| 0.672(7)&nbsp;μs
| IT
| <sup>167</sup>Os
| 13/2+
| 
| 
|-
| rowspan=2|<sup>168</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 92
| rowspan=2|167.967799(11)
| rowspan=2|2.1(1)&nbsp;s
| β<sup>+</sup> (57%)
| <sup>168</sup>Re
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (43%)
| <sup>164</sup>W
|-
| rowspan=2|<sup>169</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 93
| rowspan=2|168.967018(28)
| rowspan=2|3.46(11)&nbsp;s
| β<sup>+</sup> (86.3%)
| <sup>169</sup>Re
| rowspan=2|(5/2–)
| rowspan=2|
| rowspan=2|
|-
| α (13.7%)
| <sup>165</sup>W
|-
| rowspan=2|<sup>170</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 94
| rowspan=2|169.963579(10)
| rowspan=2|7.37(18)&nbsp;s
| β<sup>+</sup> (90.5%)
| <sup>170</sup>Re
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (9.5%)
| <sup>166</sup>W
|-
| rowspan=2|<sup>171</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 95
| rowspan=2|170.963180(20)
| rowspan=2|8.3(2)&nbsp;s
| β<sup>+</sup> (98.20%)
| <sup>171</sup>Re
| rowspan=2|(5/2−)
| rowspan=2|
| rowspan=2|
|-
| α (1.80%)
| <sup>167</sup>W
|-
| rowspan=2|<sup>172</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 96
| rowspan=2|171.960017(14)
| rowspan=2|19.2(9)&nbsp;s 
| β<sup>+</sup> (98.81%)
| <sup>172</sup>Re
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (1.19%)
| <sup>168</sup>W
|-
| rowspan=2|<sup>173</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 97
| rowspan=2|172.959808(16)
| rowspan=2|22.4(9)&nbsp;s
| β<sup>+</sup> (99.6%)
| <sup>173</sup>Re
| rowspan=2|5/2–
| rowspan=2|
| rowspan=2|
|-
| α (0.4%)
| <sup>169</sup>W
|-
| rowspan=2|<sup>174</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 98
| rowspan=2|173.957063(11)
| rowspan=2|44(4)&nbsp;s
| β<sup>+</sup> (99.98%)
| <sup>174</sup>Re
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (.024%)
| <sup>170</sup>W
|-
| <sup>175</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 99
| 174.956945(13)
| 1.4(1)&nbsp;min
| β<sup>+</sup>
| <sup>175</sup>Re
| (5/2−)
|
|
|-
| <sup>176</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 100
| 175.954770(12)
| 3.6(5)&nbsp;min
| β<sup>+</sup>
| <sup>176</sup>Re
| 0+
|
|
|-
| <sup>177</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 101
| 176.954958(16)
| 3.0(2)&nbsp;min
| β<sup>+</sup>
| <sup>177</sup>Re
| 1/2−
|
|
|-
| <sup>178</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 102
| 177.953253(15)
| 5.0(4)&nbsp;min
| β<sup>+</sup>
| <sup>178</sup>Re
| 0+
|
|
|-
| <sup>179</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 103
| 178.953816(17)
| 6.5(3)&nbsp;min
| β<sup>+</sup>
| <sup>179</sup>Re
| 1/2–
|
|
|-
| style="text-indent:1em" | <sup>179m1</sup>Os
| colspan="3" style="text-indent:2em" | 145.41(12)&nbsp;keV
| ~500&nbsp;ns        
| IT
| <sup>179</sup>Os
| (7/2)–
| 
| 
|-
| style="text-indent:1em" | <sup>179m2</sup>Os
| colspan="3" style="text-indent:2em" | 243.0(8)&nbsp;keV
| 783(14)&nbsp;ns
| IT
| <sup>179</sup>Os
| (9/2)+
| 
| 
|-
| <sup>180</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 104
| 179.952382(17)
| 21.5(4)&nbsp;min
| β<sup>+</sup>
| <sup>180</sup>Re
| 0+
|
|
|-
| <sup>181</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 105
| 180.953247(27)
| 105(3)&nbsp;min
| β<sup>+</sup>
| <sup>181</sup>Re
| 1/2−
|
|
|-
| style="text-indent:1em" | <sup>181m1</sup>Os
| colspan="3" style="text-indent:2em" | 49.20(14)&nbsp;keV
| 2.7(1)&nbsp;min
| β<sup>+</sup>
| <sup>181</sup>Re
| 7/2−
|
|
|-
| style="text-indent:1em" | <sup>181m2</sup>Os
| colspan="3" style="text-indent:2em" | 156.91(15)&nbsp;keV
| 262(6)&nbsp;ns 
| IT
| <sup>181</sup>Os
| 9/2+
|
|
|-
| <sup>182</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 106
| 181.952110(23)
| 21.84(20)&nbsp;h
| [[Physics:Electron capture|EC]]
| <sup>182</sup>Re
| 0+
|
|
|-
| style="text-indent:1em" | <sup>182m1</sup>Os
| colspan="3" style="text-indent:2em" | 1831.4(3)&nbsp;keV
| 780(70)&nbsp;μs
| IT
| <sup>182</sup>Os
| 8–
|
|
|-
| style="text-indent:1em" | <sup>182m2</sup>Os
| colspan="3" style="text-indent:2em" | 7049.5(4)&nbsp;keV
| 150(10)&nbsp;ns
| IT
| <sup>182</sup>Os
| 25+
|
|
|-
| <sup>183</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 107
| 182.953125(53)
| 13.0(5)&nbsp;h
| β<sup>+</sup>
| <sup>183</sup>Re
| 9/2+
|
|
|-
| rowspan=2 style="text-indent:1em" | <sup>183m</sup>Os
| rowspan=2 colspan="3" style="text-indent:2em" | 170.73(7)&nbsp;keV
| rowspan=2|9.9(3)&nbsp;h
| β<sup>+</sup> (85%)
| <sup>183</sup>Re
| rowspan=2|1/2−
| rowspan=2|
| rowspan=2|
|-
| IT (15%)
| <sup>183</sup>Os
|-
| <sup>184</sup>Os<ref group="n" name="PN">[[Chemistry:Primordial nuclide|primordial]] [[Physics:Radionuclide|radionuclide]]</ref>
| style="text-align:right" | 76
| style="text-align:right" | 108
| 183.95249292(89)
| '''1.12(23)×10<sup>13</sup>&nbsp;y'''
| α{{r|g=n|r=Possibly undergoing β<sup>+</sup>β<sup>+</sup> decay to '''<sup>184</sup>W'''{{NUBASE2020|ref}}}}
|'''''<sup>180</sup>W'''''
| 0+
| 2(2)×10<sup>−4</sup>
|
|-
| <sup>185</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 109
| 184.95404597(89)
| 92.95(9)&nbsp;d
| EC
| '''<sup>185</sup>Re'''
| 1/2−
|
|
|-
| style="text-indent:1em" | <sup>185m1</sup>Os
| colspan="3" style="text-indent:2em" | 102.37(11)&nbsp;keV
| 3.0(4)&nbsp;μs
| IT
| <sup>185</sup>Os
| 7/2−
|
|
|-
| style="text-indent:1em" | <sup>185m2</sup>Os
| colspan="3" style="text-indent:2em" | 275.53(12)&nbsp;keV
| 0.78(5)&nbsp;μs
| IT
| <sup>185</sup>Os
| 11/2+
|
|
|-
| <sup>186</sup>Os<ref group="n" name="PN" />
| style="text-align:right" | 76
| style="text-align:right" | 110
| 185.95383757(82)
| '''2.0(11)×10<sup>15</sup>&nbsp;y'''
| α
| '''<sup>182</sup>W'''
| 0+
| 0.0159(64)
|
|-
| <sup>187</sup>Os<ref group="n" name="RD">Used in rhenium-osmium dating</ref>
| style="text-align:right" | 76
| style="text-align:right" | 111
| 186.95574957(79)
| colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo α decay to '''<sup>183</sup>W''' with a half-life over 3.2×10<sup>15</sup>&nbsp;years</ref>
| 1/2−
| 0.0196(17)
|
|-
| style="text-indent:1em" | <sup>187m1</sup>Os
| colspan="3" style="text-indent:2em" | 100.45(4)&nbsp;keV
| 112(6)&nbsp;ns
| IT
| '''<sup>187</sup>Os'''
| 7/2−
|
|
|-
| style="text-indent:1em" | <sup>187m2</sup>Os
| colspan="3" style="text-indent:2em" | 257.10(7)&nbsp;keV
| 231(2)&nbsp;μs
| IT
| '''<sup>187</sup>Os'''
| 11/2+
|
|
|-
| <sup>188</sup>Os<ref group="n" name="RD" />
| style="text-align:right" | 76
| style="text-align:right" | 112
| 187.95583729(79)
| colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo α decay to '''<sup>184</sup>W''' with a half-life over 3.3×10<sup>18</sup>&nbsp;years</ref>
| 0+
| 0.1324(27)
|
|-
| <sup>189</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 113
| 188.95814595(72)
| colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo α decay to <sup>185</sup>W with a half-life over 3.3×10<sup>15</sup>&nbsp;years</ref>
| 3/2−
| 0.1615(23)
|
|-
| rowspan=2 style="text-indent:1em" | <sup>189m</sup>Os
| rowspan=2 colspan="3" style="text-indent:2em" | 30.82(2)&nbsp;keV
| rowspan=2|5.81(10)&nbsp;h
| IT
| '''<sup>189</sup>Os'''
| rowspan=2|9/2−
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup>
| <sup>189</sup>Ir
|-
| <sup>190</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 114
| 189.95844544(70)
| colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo α decay to '''<sup>186</sup>W''' with a half-life over 1.2×10<sup>19</sup>&nbsp;years</ref>
| 0+
| 0.2626(20)
|
|-
| style="text-indent:1em" | <sup>190m</sup>Os
| colspan="3" style="text-indent:2em" | 1705.7(1)&nbsp;keV
| 9.86(3)&nbsp;min
| IT
| '''<sup>190</sup>Os'''
| 10−
|
|
|-
| <sup>191</sup>Os 
| style="text-align:right" | 76
| style="text-align:right" | 115
| 190.96092811(71)
| 14.99(2)&nbsp;d
| β<sup>−</sup>
| '''<sup>191</sup>Ir'''
| 9/2−
|
|
|-
| style="text-indent:1em" | <sup>191m</sup>Os
| colspan="3" style="text-indent:2em" | 74.382(3)&nbsp;keV
| 13.10(5)&nbsp;h
| IT
| <sup>191</sup>Os
| 3/2−
|
|
|-
| <sup>192</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 116
| 191.9614788(25)
| colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to undergo α decay to <sup>188</sup>W or β<sup>−</sup>β<sup>−</sup> decay to '''<sup>192</sup>Pt''' with a half-life over 5.3×10<sup>19</sup>&nbsp;years</ref>
| 0+
| 0.4078(32)
|
|-
| rowspan=2 style="text-indent:1em" | <sup>192m1</sup>Os
| rowspan=2 colspan="3" style="text-indent:2em" | 2015.40(11)&nbsp;keV
| rowspan=2|5.94(9)&nbsp;s
| IT
| '''<sup>192</sup>Os'''
| rowspan=2|10−
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup>?
| <sup>192</sup>Ir
|-
| style="text-indent:1em" | <sup>192m2</sup>Os
| colspan="3" style="text-indent:2em" | 4580.3(10)&nbsp;keV
| 205(7)&nbsp;ns
| IT
| '''<sup>192</sup>Os'''
| (20+)
|
|
|-
| <sup>193</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 117
| 192.9641496(25)
| 29.830(18)&nbsp;h
| β<sup>−</sup>
| '''<sup>193</sup>Ir'''
| 3/2−
|
|
|-
| style="text-indent:1em" | <sup>193m</sup>Os
| colspan="3" style="text-indent:2em" | 315.6(3)&nbsp;keV
| 121(28)&nbsp;ns
| IT
| '''<sup>192</sup>Os'''
| (9/2−)
|
|
|-
| <sup>194</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 118
| 193.9651794(26)
| 6.0(2)&nbsp;y
| β<sup>−</sup>
| <sup>194</sup>Ir
| 0+
|
|
|-
| <sup>195</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 119
| 194.968318(60)
| 6.5(11)&nbsp;min
| β<sup>−</sup>
| <sup>195</sup>Ir
| (3/2−)
|
|
|-
| rowspan=2 style="text-indent:1em" | <sup>195m</sup>Os
| rowspan=2 colspan="3" style="text-indent:2em" | 427.8(3)&nbsp;keV
| rowspan=2|47(3)&nbsp;s
| IT
| <sup>195</sup>Os
| rowspan=2|(13/2+)
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup>?
| <sup>195</sup>Ir
|-
| <sup>196</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 120
| 195.969643(43)
| 34.9(2)&nbsp;min
| β<sup>−</sup>
| <sup>196</sup>Ir
| 0+
|
|
|-
| <sup>197</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 121
| 196.97308(22)#
| 93(7)&nbsp;s
| β<sup>−</sup>
| <sup>197</sup>Ir
| 5/2−#
|
|
|-
| <sup>198</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 122
| 197.97466(22)#
| 125(28)&nbsp;s
| β<sup>−</sup>
| <sup>198</sup>Ir
| 0+
|
|
|-
| <sup>199</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 123
| 198.97824(22)#
| 6(3)&nbsp;s
| β<sup>−</sup>
| <sup>199</sup>Ir
| 5/2−#
|
|
|-
| <sup>200</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 124
| 199.98009(32)#
| 7(4)&nbsp;s
| β<sup>−</sup>
| <sup>200</sup>Ir
| 0+
|
|
|-
| <sup>201</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 125
| 200.98407(32)#
| 3#&nbsp;s [>300ns]
| β<sup>−</sup>?
| <sup>201</sup>Ir
| 1/2−#
|
|
|-
| <sup>202</sup>Os
| style="text-align:right" | 76
| style="text-align:right" | 126
| 201.98655(43)#
| 2#&nbsp;s [>300ns]
| β<sup>−</sup>?
| <sup>202</sup>Ir
| 0+
|
|
|-
| rowspan=2|<sup>203</sup>Os
| rowspan=2 style="text-align:right" | 76
| rowspan=2 style="text-align:right" | 127
| rowspan=2|202.99220(43)#
| rowspan=2|300#&nbsp;ms [>300ns]
| β<sup>−</sup>?
| <sup>203</sup>Ir
| rowspan=2|9/2+#
| rowspan=2|
| rowspan=2|
|-
| β<sup>−</sup> n?
| <sup>202</sup>Ir
{{Isotopes table/footer}}

== References ==
{{reflist}}

* Isotope masses from:
**{{NUBASE 2003}}
* Isotopic compositions and standard atomic masses from:
**{{CIAAW 2005}}
* Half-life, spin, and isomer data selected from the following sources.
**{{NUBASE 2003}}
**{{NNDC}}
**{{CRC85|chapter=11}}

{{Navbox element isotopes}}

[[Category:Isotopes of osmium| ]]
[[Category:Osmium]]
[[Category:Lists of isotopes by element|Osmium]]

{{Sourceattribution|Isotopes of osmium|1}}