Isotopes of iridium

There are two natural isotopes of iridium (77Ir), 191Ir and 193Ir, both stable. In addition, there are 40 known radioisotopes with mass numbers 164 through 205, the most stable being 192Ir with a half-life of 73.82 days, and many nuclear isomers, the most stable of which is 192m2Ir with a half-life of 241 years. All other nuclides have half-lives under two weeks, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

The isotope 191Ir was the first one of any element to be shown to present a Mössbauer effect. This renders it useful for Mössbauer spectroscopy for research in physics, chemistry, biochemistry, metallurgy, and mineralogy.

List of isotopes

|-id=Iridium-164 | 164IrDiscovery of this isotope is unconfirmed | style="text-align:right" | 77 | style="text-align:right" | 87 | style="text-align:center" | | style="text-align:center" | 2014 | | p? | 163Os | 2#

|-id=Iridium-164m | rowspan=2 style="text-indent:1em" | 164mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 2014 | rowspan=2| | p (96%) | 163Os | rowspan=2| (9+) | rowspan=2| | rowspan=2| |- | α (4%) | 160mRe |-id=Iridium-165 | 165Ir | style="text-align:right" | 77 | style="text-align:right" | 88 | style="text-align:center" | | style="text-align:center" | 1997 | | p | 164Os | (1/2+)

|-id=Iridium-165m | rowspan=2 style="text-indent:1em" | 165mIr | rowspan=2 colspan=3 style="text-align:center" | ~ | rowspan=2 style="text-align:center" | 1997 | rowspan=2| | p (88%) | 164Os | rowspan=2|(11/2) | rowspan=2| | rowspan=2| |- | α (12%) | 161mRe |-id=Iridium-166 | rowspan=2|166Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 89 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1981 | rowspan=2| | α (93%) | 162Re | rowspan=2|(2) | rowspan=2| | rowspan=2| |- | p (7%) | 165Os |-id=Iridium-166m | rowspan=2 style="text-indent:1em" | 166mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 1997 | rowspan=2| | α (98.2%) | 162Re | rowspan=2|(9)+ | rowspan=2| | rowspan=2| |- | p (1.8%) | 165Os |-id=Iridium-167 | rowspan=3|167Ir | rowspan="3" style="text-align:right" | 77 | rowspan="3" style="text-align:right" | 90 | rowspan=3 style="text-align:center" | | rowspan=3 style="text-align:center" | 1981 | rowspan=3| | α (43.5%) | 163Re | rowspan=3|1/2+ | rowspan=3| | rowspan=3| |- | p (38.6%) | 166Os |- | β+ (17.9%) | 167Os |-id=Iridium-167m | rowspan=3 style="text-indent:1em" | 167mIr | rowspan=3 colspan=3 style="text-align:center" | | rowspan=3 style="text-align:center" | 1997 | rowspan=3| | α (89%) | 163Re | rowspan=3|11/2 | rowspan=3| | rowspan=3| |- | β+ (11%) | 167Os |- | p (0.41%) | 166Os |-id=Iridium-168 | 168Ir | style="text-align:right" | 77 | style="text-align:right" | 91 | style="text-align:center" | | style="text-align:center" | 1978 | | α | 164Re | (2)-

|-id=Iridium-168m | rowspan=3 style="text-indent:1em" | 168mIrOrder of ground state and isomer is uncertain. | rowspan=3 colspan=3 style="text-align:center" | | rowspan=3 style="text-align:center" | 1996 | rowspan=3| | α (77%) | 164Re | rowspan=3|(9,10)+ | rowspan=3| | rowspan=3| |- | β+? | 168Os |- | β+, p? | 167Re |-id=Iridium-169 | rowspan=2|169Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 92 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1978 | rowspan=2| | α (53%) | 165Re | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | β+ (47%) | 169Os |-id=Iridium-169m | rowspan=3 style="text-indent:1em" | 169mIr | rowspan=3 colspan=3 style="text-align:center" | | rowspan=3 style="text-align:center" | 1999 | rowspan=3| | α (79%) | 165Re | rowspan=3|(11/2) | rowspan=3| | rowspan=3| |- | β+? | 169Os |- | p? | 168Os |-id=Iridium-170 | rowspan=2|170Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 93 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1977 | rowspan=2| | β+ (94.8%) | 170Os | rowspan=2|(3) | rowspan=2| | rowspan=2| |- | α (5.2%) | 166Re |-id=Iridium-170m | rowspan=3 style="text-indent:1em" | 170mIr | rowspan=3 colspan=3 style="text-align:center" | #keV | rowspan=3 style="text-align:center" | 2002 | rowspan=3| | α (38%) | 166Re | rowspan=3|(8+) | rowspan=3| | rowspan=3| |- | β+? | 170Os |- | IT? | 170Ir |-id=Iridium-171 | rowspan=2|171Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 94 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (85%) | 171Os | rowspan=2|1/2+ | rowspan=2| | rowspan=2| |- | α (15%) | 167Re |-id=Iridium-171m | rowspan=3 style="text-indent:1em" | 171mIr | rowspan=3 colspan=3 style="text-align:center" | #keV | rowspan=3 style="text-align:center" | 2002 | rowspan=3| | α (54%) | 167Re | rowspan=3|(11/2) | rowspan=3| | rowspan=3| |- | β+? | 171Os |- | p? | 170Os |-id=Iridium-172 | rowspan=2|172Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 95 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (~98%) | 172Os | rowspan=2|(3,4) | rowspan=2| | rowspan=2| |- | α (~2%) | 168Re |-id=Iridium-172m | rowspan=2 style="text-indent:1em" | 172mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 1992 | rowspan=2| | β+ (90.5%) | 172Os | rowspan=2|(7+) | rowspan=2| | rowspan=2| |- | α (9.5%) | 168Re |-id=Iridium-173 | rowspan=2|173Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 96 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (96.5%) | 173Os | rowspan=2|(1/2+,3/2+) | rowspan=2| | rowspan=2| |- | α (3.5%) | 169Re |-id=Iridium-173m | rowspan=2 style="text-indent:1em" | 173mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 1992 | rowspan=2| | β+ (88%) | 173Os | rowspan=2|11/2 | rowspan=2| | rowspan=2| |- | α (12%) | 169Re |-id=Iridium-174 | rowspan=2|174Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 97 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (99.5%) | 174Os | rowspan=2|(2+,3) | rowspan=2| | rowspan=2| |- | α (0.5%) | 170Re |-id=Iridium-174m | rowspan=2 style="text-indent:1em" | 174mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 1992 | rowspan=2| | β+ (97.5%) | 174Os | rowspan=2|(6,7,8,9) | rowspan=2| | rowspan=2| |- | α (2.5%) | 170Re |-id=Iridium-175 | rowspan=2|175Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 98 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (99.15%) | 175Os | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | α (0.85%) | 171Re |-id=Iridium-175m1 | style="text-indent:1em" | 175m1Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 2010 | | β+ | 175Os | 9/2#

|-id=Iridium-175m2 | style="text-indent:1em" | 175m2Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 2019 | | IT | 175Ir | (5/2)

|-id=Iridium-176 | rowspan=2|176Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 99 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (96.9%) | 176Os | rowspan=2|(3+) | rowspan=2| | rowspan=2| |- | α (3.1%) | 172Re |-id=Iridium-177 | rowspan=2|177Ir | rowspan="2" style="text-align:right" | 77 | rowspan="2" style="text-align:right" | 100 | rowspan=2 style="text-align:center" | | rowspan=2 style="text-align:center" | 1967 | rowspan=2| | β+ (99.94%) | 177Os | rowspan=2|5/2 | rowspan=2| | rowspan=2| |- | α (0.06%) | 173Re |-id=Iridium-177m | style="text-indent:1em" | 177mIr | colspan=3 style="text-align:center" | | style="text-align:center" | (1991) Half-life not measured, not included in discovery database | | IT | 177Ir | (5/2+)

|-id=Iridium-178 | 178Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 101 | style="text-align:center" | | style="text-align:center" | 1972 | | β+ | 178Os | 3+#

|-id=Iridium-179 | 179Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 102 | style="text-align:center" | | style="text-align:center" | 1992 | | β+ | 179Os | (5/2)

|-id=Iridium-180 | 180Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 103 | style="text-align:center" | | style="text-align:center" | 1972 | | β+ | 180Os | (5+)

|-id=Iridium-181 | 181Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 104 | style="text-align:center" | | style="text-align:center" | 1972 | | β+ | 181Os | 5/2

|-id=Iridium-181m1 | style="text-indent:1em" | 181m1Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1992 | | IT | 181Ir | 5/2+

|-id=Iridium-181m2 | style="text-indent:1em" | 181m2Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1990 | | IT | 181Ir | 9/2

|-id=Iridium-182 | 182Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 105 | style="text-align:center" | | style="text-align:center" | 1961 | | β+ | 182Os | 3+

|-id=Iridium-182m1 | style="text-indent:1em" | 182m1Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1990 | | IT | 182Ir | (5)+

|-id=Iridium-182m2 | style="text-indent:1em" | 182m2Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1990 | | IT | 182Ir | (6)

|-id=Iridium-183 | 183Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 106 | style="text-align:center" | | style="text-align:center" | 1961 | | β+ | 183Os | 5/2

|-id=Iridium-184 | 184Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 107 | style="text-align:center" | | style="text-align:center" | 1960 | | β+ | 184Os | 5

|-id=Iridium-184m1 | style="text-indent:1em" | 184m1Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1988 | | IT | 184Ir | 3+

|-id=Iridium-184m2 | style="text-indent:1em" | 184m2Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1988 | | IT | 184Ir | 7+

|-id=Iridium-185 | 185Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 108 | style="text-align:center" | | style="text-align:center" | 1958 | | β+ | 185Os | 5/2

|-id=Iridium-185m | style="text-indent:1em" | 185mIr | colspan=3 style="text-align:center" | | style="text-align:center" | 1979 | | IT | 185Ir | (23/2,25/2)#

|-id=Iridium-186 | 186Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 109 | style="text-align:center" | | style="text-align:center" | 1958 | | β+ | 186Os | 5+

|-id=Iridium-186m | rowspan=2 style="text-indent:1em" | 186mIr | rowspan=2 colspan=3 style="text-align:center" | | rowspan=2 style="text-align:center" | 1962 | rowspan=2| | β+ (~75%) | 186Os | rowspan=2|2 | rowspan=2| | rowspan=2| |- | IT (~25%) | 186Ir |-id=Iridium-187 | 187Ir |rowspan="1" style="text-align:right" | 77 |rowspan="1" style="text-align:right" | 110 | style="text-align:center" | | style="text-align:center" | 1958 | | β+ | 187Os | 3/2+

|-id=Iridium-187m1 | style="text-indent:1em" | 187m1Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1963 | | IT | 187Ir | 9/2

|-id=Iridium-187m2 | style="text-indent:1em" | 187m2Ir | colspan=3 style="text-align:center" | | style="text-align:center" | 1969 | | IT | 187Ir | 11/2

|-id=Iridium-187m3 | style="text-indent:1em" | 187m3Ir