# Isotopes of rhodium

Naturally occurring rhodium ($_{45}$Rh) is composed of only one stable isotope, $^{103}$Rh. The most stable radioisotopes are $^{101}$Rh with a half-life of 3.3 years, $^{102}$Rh with a half-life of 207 days, and $^{99}$Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u ($^{89}$Rh) to 121.943 u ($^{122}$Rh). Most of these have half-lives that are less than an hour except $^{100}$Rh (half-life: 20.8 hours) and $^{105}$Rh (half-life: 35.36 hours). There are also numerous meta states with the most stable being $^{102m}$Rh (0.141 MeV) with a half-life of about 3.7 years and $^{101m}$Rh (0.157 MeV) with a half-life of 4.34 days. The primary decay mode before the only stable isotope, $^{103}$Rh, is electron capture and the primary mode after is beta emission. The primary decay product before $^{103}$Rh is ruthenium and the primary product after is palladium.

## List of isotopes

| Nuclide | Z | N | Isotopic mass (Da) | Half-life | Decay mode | Daughter isotope | Spin and parity | Isotopic abundance |
| Isotopic abundance |||
| $^{90}$Rh | 45 | 45 | 89.94457(22)# | 29(3) ms | β$^+$ | $^{90}$Ru | (0+) | |
| $^{90}$Rh | 45 | 45 | 89.94457(22)# | 29(3) ms | β$^+$, p? (<0.7%) | $^{89}$Tc | (0+) | |
| $^{90m}$Rh | 0(500)# keV | 0(500)# keV | 0(500)# keV | 0.56(2) s | β$^+$ (90.4%) | $^{90}$Ru | (7+) | |
| $^{90m}$Rh | 0(500)# keV | 0(500)# keV | 0(500)# keV | 0.56(2) s | β$^+$, p (9.6%) | $^{89}$Tc | (7+) | |
| $^{91}$Rh | 45 | 46 | 90.93712(32)# | 1.47(22) s | β$^+$ (98.7%) | $^{91}$Ru | (9/2+) | |
| $^{91}$Rh | 45 | 46 | 90.93712(32)# | 1.47(22) s | β$^+$, p (1.3%) | $^{90}$Tc | (9/2+) | |
| $^{91m}$Rh | 172.9(4) keV | 172.9(4) keV | 172.9(4) keV | 1.8# s | β$^+$? | $^{91}$Ru | 1/2−# | |
| $^{91m}$Rh | 172.9(4) keV | 172.9(4) keV | 172.9(4) keV | 1.8# s | β$^+$, p? | $^{90}$Tc | 1/2−# | |
| $^{91m}$Rh | 172.9(4) keV | 172.9(4) keV | 172.9(4) keV | 1.8# s | IT? | $^{91}$Rh | 1/2−# | |
| $^{92}$Rh | 45 | 47 | 91.9323677(47) | 5.61(8) s | β$^+$ (97.95%) | $^{92}$Ru | (6+) | |
| $^{92}$Rh | 45 | 47 | 91.9323677(47) | 5.61(8) s | β$^+$, p (2.05%) | $^{91}$Tc | (6+) | |
| $^{92m1}$Rh | 50(100)# keV | 50(100)# keV | 50(100)# keV | 3.18(22) s | β$^+$ (98.3%) | $^{92}$Ru | (2+) | |
| $^{92m1}$Rh | 50(100)# keV | 50(100)# keV | 50(100)# keV | 3.18(22) s | β$^+$, p (1.7%) | $^{91}$Tc | (2+) | |
| $^{92m2}$Rh | 105(100)# keV | 105(100)# keV | 105(100)# keV | 232(15) ns | IT | $^{92}$Rh | (4+) | |
| $^{93}$Rh | 45 | 48 | 92.9259128(28) | 13.9(16) s | β$^+$ | $^{93}$Ru | 9/2+# | |
| $^{94}$Rh | 45 | 49 | 93.9217305(36) | 70.6(6) s | β$^+$ (98.2%) | $^{94}$Ru | (4+) | |
| $^{94}$Rh | 45 | 49 | 93.9217305(36) | 70.6(6) s | β$^+$, p (1.8%) | $^{93}$Tc | (4+) | |
| $^{94m1}$Rh | 54.60(20)# keV | 54.60(20)# keV | 54.60(20)# keV | 480(30) ns | IT | $^{94}$Rh | (2+) | |
| $^{94m2}$Rh | 300(200)# keV | 300(200)# keV | 300(200)# keV | 25.8(2) s | β$^+$ | $^{94}$Ru | (8+) | |
| $^{95}$Rh | 45 | 50 | 94.9158979(42) | 5.02(10) min | β$^+$ | $^{95}$Ru | (9/2)+ | |
| $^{95m}$Rh | 543.3(3) keV | 543.3(3) keV | 543.3(3) keV | 1.96(4) min | IT (88%) | $^{95}$Rh | (1/2)− | |
| $^{95m}$Rh | 543.3(3) keV | 543.3(3) keV | 543.3(3) keV | 1.96(4) min | β$^+$ (12%) | $^{95}$Ru | (1/2)− | |
| $^{96}$Rh | 45 | 51 | 95.914452(11) | 9.90(10) min | β$^+$ | $^{96}$Ru | 6+ | |
| $^{96m}$Rh | 51.98(9) keV | 51.98(9) keV | 51.98(9) keV | 1.51(2) min | IT (60%) | $^{96}$Rh | 3+ | |
| $^{96m}$Rh | 51.98(9) keV | 51.98(9) keV | 51.98(9) keV | 1.51(2) min | β$^+$ (40%) | $^{96}$Ru | 3+ | |
| $^{97}$Rh | 45 | 52 | 96.911328(38) | 30.7(6) min | β$^+$ | $^{97}$Ru | 9/2+ | |
| $^{97m}$Rh | 258.76(18) keV | 258.76(18) keV | 258.76(18) keV | 46.2(16) min | β$^+$ (94.4%) | $^{97}$Ru | 1/2− | |
| $^{97m}$Rh | 258.76(18) keV | 258.76(18) keV | 258.76(18) keV | 46.2(16) min | IT (5.6%) | $^{97}$Rh | 1/2− | |
| $^{98}$Rh | 45 | 53 | 97.910708(13) | 8.72(12) min | β$^+$ | $^{98}$Ru | (2)+ | |
| $^{98m}$Rh | 56.3(10) keV | 56.3(10) keV | 56.3(10) keV | 3.6(2) min | IT (89%) | $^{98}$Rh | (5+) | |
| $^{98m}$Rh | 56.3(10) keV | 56.3(10) keV | 56.3(10) keV | 3.6(2) min | β$^+$ (11%) | $^{98}$Ru | (5+) | |
| $^{99}$Rh | 45 | 54 | 98.908121(21) | 16.1(2) d | β$^+$ | $^{99}$Ru | 1/2− | |
| $^{99m}$Rh | 64.4(5) keV | 64.4(5) keV | 64.4(5) keV | 4.7(1) h | β$^+$ | $^{99}$Ru | 9/2+ | |
| $^{99m}$Rh | 64.4(5) keV | 64.4(5) keV | 64.4(5) keV | 4.7(1) h | IT? | $^{99}$Rh | 9/2+ | |
| $^{100}$Rh | 45 | 55 | 99.908114(19) | 20.8(1) h | EC (95.1%) | $^{100}$Ru | 1− | |
| $^{100}$Rh | 45 | 55 | 99.908114(19) | 20.8(1) h | β$^+$ (4.9%) | $^{100}$Ru | 1− | |
| $^{100m1}$Rh | 74.782(14) keV | 74.782(14) keV | 74.782(14) keV | 214.0(20) ns | IT | $^{100}$Rh | (2)+ | |
| $^{100m2}$Rh | 107.6(2) keV | 107.6(2) keV | 107.6(2) keV | 4.6(2) min | IT (98.3%) | $^{100}$Rh | (5+) | |
| $^{100m2}$Rh | 107.6(2) keV | 107.6(2) keV | 107.6(2) keV | 4.6(2) min | β$^+$ (1.7%) | $^{100}$Ru | (5+) | |
| $^{100m3}$Rh | 219.61(22) keV | 219.61(22) keV | 219.61(22) keV | 130(10) ns | IT | $^{100}$Rh | (7+) | |
| $^{101}$Rh | 45 | 56 | 100.9061589(63) | 4.07(5) y | EC | $^{101}$Ru | 1/2− | |
| $^{101m}$Rh | 157.32(3) keV | 157.32(3) keV | 157.32(3) keV | 4.343(10) d | EC (92.80%) | $^{101}$Ru | 9/2+ | |
| $^{101m}$Rh | 157.32(3) keV | 157.32(3) keV | 157.32(3) keV | 4.343(10) d | IT (7.20%) | $^{101}$Rh | 9/2+ | |
| $^{102}$Rh | 45 | 57 | 101.9068343(69) | 207.0(15) d | β$^+$ (78%) | $^{102}$Ru | 2− | |
| $^{102}$Rh | 45 | 57 | 101.9068343(69) | 207.0(15) d | β$^−$ (22%) | $^{102}$Pd | 2− | |
| $^{102m}$Rh | 140.73(9) keV | 140.73(9) keV | 140.73(9) keV | 3.742(10) y | β$^+$ (99.77%) | $^{102}$Ru | 6+ | |
| $^{102m}$Rh | 140.73(9) keV | 140.73(9) keV | 140.73(9) keV | 3.742(10) y | IT (0.233%) | $^{102}$Rh | 6+ | |
| $^{103}$Rh | 45 | 58 | 102.9054941(25) | Stable | Stable | Stable | 1/2− | 1.0000 |
| $^{103m}$Rh | 39.753(6) keV | 39.753(6) keV | 39.753(6) keV | 56.114(9) min | IT | $^{103}$Rh | 7/2+ | |
| $^{104}$Rh | 45 | 59 | 103.9066453(25) | 42.3(4) s | β$^−$ (99.55%) | $^{104}$Pd | 1+ | |
| $^{104}$Rh | 45 | 59 | 103.9066453(25) | 42.3(4) s | β$^+$ (0.45%) | $^{104}$Ru | 1+ | |
| $^{104m}$Rh | 128.9679(5) keV | 128.9679(5) keV | 128.9679(5) keV | 4.34(3) min | IT (99.87%) | $^{104}$Rh | 5+ | |
| $^{104m}$Rh | 128.9679(5) keV | 128.9679(5) keV | 128.9679(5) keV | 4.34(3) min | β$^−$ (0.13%) | $^{104}$Pd | 5+ | |
| $^{105}$Rh | 45 | 60 | 104.9056878(27) | 35.341(19) h | β$^−$ | $^{105}$Pd | 7/2+ | |
| $^{105m}$Rh | 129.742(4) keV | 129.742(4) keV | 129.742(4) keV | 42.8(3) s | IT | $^{105}$Rh | 1/2− | |
| $^{106}$Rh | 45 | 61 | 105.9072859(58) | 30.07(35) s | β$^−$ | $^{106}$Pd | 1+ | |
| $^{106m}$Rh | 132(11) keV | 132(11) keV | 132(11) keV | 131(2) min | β$^−$ | $^{106}$Pd | (6)+ | |
| $^{107}$Rh | 45 | 62 | 106.906748(13) | 21.7(4) min | β$^−$ | $^{107}$Pd | 7/2+ |
| $^{107m}$Rh | 268.36(4) keV | 268.36(4) keV | 268.36(4) keV | >10 μs | IT | $^{107}$Rh | 1/2− | |
| $^{108}$Rh | 45 | 63 | 107.908715(15) | 16.8(5) s | β$^−$ | $^{108}$Pd | 1+ | |
| $^{108m}$Rh | 115(18) keV | 115(18) keV | 115(18) keV | 6.0(3) min | β$^−$ | $^{108}$Pd | (5+) | |
| $^{109}$Rh | 45 | 64 | 108.9087496(43) | 80.8(7) s | β$^−$ | $^{109}$Pd | 7/2+ | |
| $^{109m}$Rh | 225.873(19) keV | 225.873(19) keV | 225.873(19) keV | 1.66(4) μs | IT | $^{109}$Pd | 3/2+ | |
| $^{110}$Rh | 45 | 65 | 109.911080(19) | 3.35(12) s | β$^−$ | $^{110}$Pd | (1+) | |
| $^{110m}$Rh | 220(150)# keV | 220(150)# keV | 220(150)# keV | 28.5(13) s | β$^−$ | $^{110}$Pd | (6+) | |
| $^{111}$Rh | 45 | 66 | 110.9116432(74) | 11(1) s | β$^−$ | $^{111}$Pd | (7/2+) | |
| $^{112}$Rh | 45 | 67 | 111.914405(47) | 3.4(4) s | β$^−$ | $^{112}$Pd | (1+) | |
| $^{112m}$Rh | 340(70) keV | 340(70) keV | 340(70) keV | 6.73(15) s | β$^−$ | $^{112}$Pd | (6+) | |
| $^{113}$Rh | 45 | 68 | 112.9154402(77) | 2.80(12) s | β$^−$ | $^{113}$Pd | (7/2+) | |
| $^{114}$Rh | 45 | 69 | 113.918722(77) | 1.85(5) s | β$^−$ | $^{114}$Pd | 1+ | |
| $^{114m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 1.85(5) s | β$^−$ | $^{114}$Pd | (7−) | |
| $^{115}$Rh | 45 | 70 | 114.9203116(79) | 1.03(3) s | β$^−$ | $^{115}$Pd | (7/2+) | |
| $^{115}$Rh | 45 | 70 | 114.9203116(79) | 1.03(3) s | β$^−$, n? | $^{114}$Pd | (7/2+) | |
| $^{116}$Rh | 45 | 71 | 115.924062(79) | 685(39) ms | β$^−$ (>97.9%) | $^{116}$Pd | 1+ | |
| $^{116}$Rh | 45 | 71 | 115.924062(79) | 685(39) ms | β$^−$, n? (<2.1%) | $^{115}$Pd | 1+ | |
| $^{116m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 570(50) ms | β$^−$ (>97.9%) | $^{116}$Pd | (6−) | |
| $^{116m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 570(50) ms | β$^−$, n? (<2.1%) | $^{115}$Pd | (6−) | |
| $^{117}$Rh | 45 | 72 | 116.9260363(95) | 421(30) ms | β$^−$ | $^{117}$Pd | 7/2+# | |
| $^{117}$Rh | 45 | 72 | 116.9260363(95) | 421(30) ms | β$^−$, n? (<7.6%) | $^{116}$Pd | 7/2+# | |
| $^{117m}$Rh | 321.2(10) keV | 321.2(10) keV | 321.2(10) keV | 138(17) ns | IT | $^{117}$Rh | 3/2+# | |
| $^{118}$Rh | 45 | 73 | 117.930341(26) | 282(9) ms | β$^−$ (96.9%) | $^{118}$Pd | 1+# | |
| $^{118}$Rh | 45 | 73 | 117.930341(26) | 282(9) ms | β$^−$, n (3.1%) | $^{117}$Pd | 1+# | |
| $^{118m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 310(30) ms | β$^−$ (96.9%) | $^{118}$Pd | 6−# | |
| $^{118m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 310(30) ms | β$^−$, n (3.1%) | $^{117}$Pd | 6−# | |
| $^{118m}$Rh | 200(150)# keV | 200(150)# keV | 200(150)# keV | 310(30) ms | IT? | $^{118}$Rh | 6−# | |
| $^{119}$Rh | 45 | 74 | 118.932557(10) | 190(6) ms | β$^−$ (93.6%) | $^{119}$Pd | 7/2+# | |
| $^{119}$Rh | 45 | 74 | 118.932557(10) | 190(6) ms | β$^−$, n (6.4%) | $^{118}$Pd | 7/2+# | |
| $^{120}$Rh | 45 | 75 | 119.93707(22)# | 129.6(42) ms | β$^−$ | $^{120}$Pd | 8−# | |
| $^{120}$Rh | 45 | 75 | 119.93707(22)# | 129.6(42) ms | β$^−$, n (<9.3%) | $^{119}$Pd | 8−# | |
| $^{120}$Rh | 45 | 75 | 119.93707(22)# | 129.6(42) ms | β$^−$, 2n? | $^{118}$Pd | 8−# | |
| $^{120m}$Rh | 157.2(7) keV | 157.2(7) keV | 157.2(7) keV | 295(16) ns | IT | $^{120}$Rh | 6# | |
| $^{121}$Rh | 45 | 76 | 120.93961(67) | 74(4) ms | β$^−$ | $^{121}$Pd | 7/2+# | |
| $^{121}$Rh | 45 | 76 | 120.93961(67) | 74(4) ms | β$^−$, n (>11%) | $^{120}$Pd | 7/2+# | |
| $^{122}$Rh | 45 | 77 | 121.94431(32)# | 51(6) ms | β$^−$ | $^{122}$Pd | 7−# | |
| $^{122}$Rh | 45 | 77 | 121.94431(32)# | 51(6) ms | β$^−$, n (<3.9%) | $^{121}$Pd | 7−# | |
| $^{122}$Rh | 45 | 77 | 121.94431(32)# | 51(6) ms | β$^−$, 2n? | $^{120}$Pd | 7−# | |
| $^{122m}$Rh | 271.0(7) keV | 271.0(7) keV | 271.0(7) keV | 830(120) ns | IT | $^{122}$Rh | 4+# | |
| $^{123}$Rh | 45 | 78 | 122.94719(43)# | 42(4) ms | β$^−$ | $^{123}$Pd | 7/2+# | |
| $^{123}$Rh | 45 | 78 | 122.94719(43)# | 42(4) ms | β$^−$, n (>24%) | $^{122}$Pd | 7/2+# | |
| $^{123}$Rh | 45 | 78 | 122.94719(43)# | 42(4) ms | β$^−$, 2n? | $^{121}$Pd | 7/2+# | |
| $^{124}$Rh | 45 | 79 | 123.95200(43)# | 30(2) ms | β$^−$ | $^{124}$Pd | 2+# | |
| $^{124}$Rh | 45 | 79 | 123.95200(43)# | 30(2) ms | β$^−$, n (<31%) | $^{123}$Pd | 2+# | |
| $^{124}$Rh | 45 | 79 | 123.95200(43)# | 30(2) ms | β$^−$, 2n? | $^{122}$Pd | 2+# | |
| $^{125}$Rh | 45 | 80 | 124.95509(54)# | 26.5(20) ms | β$^−$ | $^{125}$Pd | 7/2+# | |
| $^{125}$Rh | 45 | 80 | 124.95509(54)# | 26.5(20) ms | β$^−$, n? | $^{124}$Pd | 7/2+# | |
| $^{125}$Rh | 45 | 80 | 124.95509(54)# | 26.5(20) ms | β$^−$, 2n? | $^{123}$Pd | 7/2+# | |
| $^{126}$Rh | 45 | 81 | 125.96006(54)# | 19(3) ms | β$^−$ | $^{126}$Pd | 1−# | |
| $^{126}$Rh | 45 | 81 | 125.96006(54)# | 19(3) ms | β$^−$, n? | $^{125}$Pd | 1−# | |
| $^{126}$Rh | 45 | 81 | 125.96006(54)# | 19(3) ms | β$^−$, 2n? | $^{124}$Pd | 1−# | |
| $^{127}$Rh | 45 | 82 | 126.96379(64)# | 28(14) ms | β$^−$ | $^{127}$Pd | 7/2+# | |
| $^{127}$Rh | 45 | 82 | 126.96379(64)# | 28(14) ms | β$^−$, n? | $^{126}$Pd | 7/2+# | |
| $^{127}$Rh | 45 | 82 | 126.96379(64)# | 28(14) ms | β$^−$, 2n? | $^{125}$Pd | 7/2+# | |
| $^{128}$Rh | 45 | 83 | 127.97065(32)# | 8# ms [>550 ns] | β$^−$? | $^{128}$Pd | | |
| $^{128}$Rh | 45 | 83 | 127.97065(32)# | 8# ms [>550 ns] | β$^−$, n? | $^{127}$Pd | | |
| $^{128}$Rh | 45 | 83 | 127.97065(32)# | 8# ms [>550 ns] | β$^−$, 2n? | $^{126}$Pd | | |
| This table header & footer: view |||||||||
* ↑ $^m$Rh – Excited nuclear isomer.
* ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
* ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
* 1 2 3 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
* ↑ Modes of decay: EC:Electron capture IT:Isomeric transition n:Neutron emission p:Proton emission
* ↑ Bold symbol as daughter – Daughter product is stable.
* ↑ ( ) spin value – Indicates spin with weak assignment arguments.
* 1 2 3 4 5 6 7 Order of ground state and isomer is uncertain.
* 1 2 Fission product