Isotopes of rhodium explained

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh.^[1] The most stable radioisotopes are ¹⁰¹Rh with a half-life of 3.3 years, ¹⁰²Rh with a half-life of 207 days, and ⁹⁹Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (⁸⁹Rh) to 121.943 u (¹²²Rh). Most of these have half-lives that are less than an hour except ¹⁰⁰Rh (half-life: 20.8 hours) and ¹⁰⁵Rh (half-life: 35.36 hours). There are also numerous meta states with the most stable being ^102mRh (0.141 MeV) with a half-life of about 3.7 years and ^101mRh (0.157 MeV) with a half-life of 4.34 days.

The primary decay mode before the only stable isotope, ¹⁰³Rh, is electron capture and the primary mode after is beta emission. The primary decay product before ¹⁰³Rh is ruthenium and the primary product after is palladium.

List of isotopes

|-| rowspan=2|⁹⁰Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 45| rowspan=2|89.94457(22)#| rowspan=2|29(3) ms| β⁺| ⁹⁰Ru| rowspan=2|(0+)| rowspan=2||-| β⁺, p? (<0.7%)| ⁸⁹Tc|-| rowspan=2 style="text-indent:1em" | ^90mRh^[2] | rowspan=2 colspan="3" style="text-indent:2em" | 0(500)# keV| rowspan=2|0.56(2) s| β⁺ (90.4%)| ⁹⁰Ru| rowspan=2|(7+)| rowspan=2||-| β⁺, p (9.6%)| ⁸⁹Tc|-| rowspan=2|⁹¹Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 46| rowspan=2|90.93712(32)#| rowspan=2|1.47(22) s| β⁺ (98.7%)| ⁹¹Ru| rowspan=2|(9/2+)| rowspan=2||-| β⁺, p (1.3%)| ⁹⁰Tc|-| rowspan=3 style="text-indent:1em" | ^91mRh| rowspan=3 colspan="3" style="text-indent:2em" | 172.9(4) keV| rowspan=3|1.8# s| β⁺?| ⁹¹Ru| rowspan=3|1/2−#| rowspan=3||-| β⁺, p?| ⁹⁰Tc|-| IT?| ⁹¹Rh|-| rowspan=2|⁹²Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 47| rowspan=2|91.9323677(47)| rowspan=2|5.61(8) s| β⁺ (97.95%)| ⁹²Ru| rowspan=2|(6+)| rowspan=2||-| β⁺, p (2.05%)| ⁹¹Tc|-| rowspan=2 style="text-indent:1em" | ^92m1Rh| rowspan=2 colspan="3" style="text-indent:2em" | 50(100)# keV| rowspan=2|3.18(22) s| β⁺ (98.3%)| ⁹²Ru| rowspan=2|(2+)| rowspan=2||-| β⁺, p (1.7%)| ⁹¹Tc|-| style="text-indent:1em" | ^92m2Rh| colspan="3" style="text-indent:2em" | 105(100)# keV| 232(15) ns| IT| ⁹²Rh| (4+)| |-| ⁹³Rh| style="text-align:right" | 45| style="text-align:right" | 48| 92.9259128(28)| 13.9(16) s| β⁺| ⁹³Ru| 9/2+#||-| rowspan=2|⁹⁴Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 49| rowspan=2|93.9217305(36)| rowspan=2|70.6(6) s| β⁺ (98.2%)| ⁹⁴Ru| rowspan=2|(4+)| rowspan=2||-| β⁺, p (1.8%)| ⁹³Tc|-| style="text-indent:1em" | ^94m1Rh| colspan="3" style="text-indent:2em" | 54.60(20)# keV| 480(30) ns| IT| ⁹⁴Rh| (2+)| |-| style="text-indent:1em" | ^94m2Rh^[2] | colspan="3" style="text-indent:2em" | 300(200)# keV| 25.8(2) s| β⁺| ⁹⁴Ru| (8+)| |-| ⁹⁵Rh| style="text-align:right" | 45| style="text-align:right" | 50| 94.9158979(42)| 5.02(10) min| β⁺| ⁹⁵Ru| (9/2)+||-| rowspan=2 style="text-indent:1em" | ^95mRh| rowspan=2 colspan="3" style="text-indent:2em" | 543.3(3) keV| rowspan=2|1.96(4) min| IT (88%)| ⁹⁵Rh| rowspan=2|(1/2)−| rowspan=2||-| β⁺ (12%)| ⁹⁵Ru|-| ⁹⁶Rh| style="text-align:right" | 45| style="text-align:right" | 51| 95 914452(11)| 9.90(10) min| β⁺| ⁹⁶Ru| 6+||-| rowspan=2 style="text-indent:1em" | ^96mRh| rowspan=2 colspan="3" style="text-indent:2em" | 51.98(9) keV| rowspan=2|1.51(2) min| IT (60%)| ⁹⁶Rh| rowspan=2|3+| rowspan=2||-| β⁺ (40%)| ⁹⁶Ru|-| ⁹⁷Rh| style="text-align:right" | 45| style="text-align:right" | 52| 96.911328(38)| 30.7(6) min| β⁺| ⁹⁷Ru| 9/2+||-| rowspan=2 style="text-indent:1em" | ^97mRh| rowspan=2 colspan="3" style="text-indent:2em" | 258.76(18) keV| rowspan=2|46.2(16) min| β⁺ (94.4%)| ⁹⁷Ru| rowspan=2|1/2−| rowspan=2||-| IT (5.6%)| ⁹⁷Rh|-| ⁹⁸Rh| style="text-align:right" | 45| style="text-align:right" | 53| 97.910708(13)| 8.72(12) min| β⁺| ⁹⁸Ru| (2)+||-| rowspan=2 style="text-indent:1em" | ^98mRh^[2] | rowspan=2 colspan="3" style="text-indent:2em" | 56.3(10) keV| rowspan=2|3.6(2) min| IT (89%)| ⁹⁸Rh| rowspan=2|(5+)| rowspan=2||-| β⁺ (11%)| ⁹⁸Ru|-| ⁹⁹Rh| style="text-align:right" | 45| style="text-align:right" | 54| 98.908121(21)| 16.1(2) d| β⁺| ⁹⁹Ru| 1/2−||-| rowspan=2 style="text-indent:1em" | ^99mRh| rowspan=2 colspan="3" style="text-indent:2em" | 64.4(5) keV| rowspan=2|4.7(1) h| β⁺| ⁹⁹Ru| rowspan=2|9/2+| rowspan=2||-| IT?| ⁹⁹Rh|- | rowspan=2|¹⁰⁰Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 55| rowspan=2|99.908114(19)| rowspan=2|20.8(1) h| EC (95.1%)| ¹⁰⁰Ru| rowspan=2|1−| rowspan=2||-| β⁺ (4.9%)| ¹⁰⁰Ru|-| style="text-indent:1em" | ^100m1Rh| colspan="3" style="text-indent:2em" | 74.782(14) keV| 214.0(20) ns| IT| ¹⁰⁰Rh| (2)+| |-| rowspan=2 style="text-indent:1em" | ^100m2Rh| rowspan=2 colspan="3" style="text-indent:2em" | 107.6(2) keV| rowspan=2|4.6(2) min| IT (98.3%)| ¹⁰⁰Rh| rowspan=2|(5+)| rowspan=2||-| β⁺ (1.7%)| ¹⁰⁰Ru|-| style="text-indent:1em" | ^100m3Rh| colspan="3" style="text-indent:2em" | 219.61(22) keV| 130(10) ns| IT| ¹⁰⁰Rh| (7+)||-| ¹⁰¹Rh| style="text-align:right" | 45| style="text-align:right" | 56| 100.9061589(63)| 4.07(5) y| EC| ¹⁰¹Ru| 1/2−||-| rowspan=2 style="text-indent:1em" | ^101mRh| rowspan=2 colspan="3" style="text-indent:2em" | 157.32(3) keV| rowspan=2|4.343(10) d| EC (92.80%)| ¹⁰¹Ru| rowspan=2|9/2+| rowspan=2||-| IT (7.20%)| ¹⁰¹Rh|-| rowspan=2|¹⁰²Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 57| rowspan=2|101.9068343(69)| rowspan=2|207.0(15) d| β⁺ (78%)| ¹⁰²Ru| rowspan=2|2−| rowspan=2||-| β⁻ (22%)| ¹⁰²Pd|-| rowspan=2 style="text-indent:1em" | ^102mRh| rowspan=2 colspan="3" style="text-indent:2em" | 140.73(9) keV| rowspan=2|3.742(10) y| β⁺ (99.77%)| ¹⁰²Ru| rowspan=2|6+| rowspan=2||-| IT (0.233%)| ¹⁰²Rh|-| ¹⁰³Rh^[3] | style="text-align:right" | 45| style="text-align:right" | 58| 102.9054941(25)| colspan=3 align=center|Stable| 1/2−| 1.0000|-| style="text-indent:1em" | ^103mRh| colspan="3" style="text-indent:2em" | 39.753(6) keV| 56.114(9) min| IT| ¹⁰³Rh| 7/2+||-| rowspan=2|¹⁰⁴Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 59| rowspan=2|103.9066453(25)| rowspan=2|42.3(4) s| β⁻ (99.55%)| ¹⁰⁴Pd| rowspan=2|1+| rowspan=2||-| β⁺ (0.45%)| ¹⁰⁴Ru|-| rowspan=2 style="text-indent:1em" | ^104mRh| rowspan=2 colspan="3" style="text-indent:2em" | 128.9679(5) keV| rowspan=2|4.34(3) min| IT (99.87%)| ¹⁰⁴Rh| rowspan=2|5+| rowspan=2||-| β⁻ (0.13%)| ¹⁰⁴Pd|-| ¹⁰⁵Rh| style="text-align:right" | 45| style="text-align:right" | 60| 104.9056878(27)| 35.341(19) h| β⁻| ¹⁰⁵Pd| 7/2+||-| style="text-indent:1em" | ^105mRh| colspan="3" style="text-indent:2em" | 129.742(4) keV| 42.8(3) s| IT| ¹⁰⁵Rh| 1/2−| |- | ¹⁰⁶Rh| style="text-align:right" | 45| style="text-align:right" | 61| 105.9072859(58)| 30.07(35) s| β⁻| ¹⁰⁶Pd| 1+||-| style="text-indent:1em" | ^106mRh| colspan="3" style="text-indent:2em" | 132(11) keV| 131(2) min| β⁻| ¹⁰⁶Pd| (6)+||-| ¹⁰⁷Rh| style="text-align:right" | 45| style="text-align:right" | 62| 106.906748(13)| 21.7(4) min| β⁻| ¹⁰⁷Pd| 7/2+|-| style="text-indent:1em" | ^107mRh| colspan="3" style="text-indent:2em" | 268.36(4) keV| >10 μs| IT| ¹⁰⁷Rh| 1/2−||-| ¹⁰⁸Rh| style="text-align:right" | 45| style="text-align:right" | 63| 107.908715(15)| 16.8(5) s| β⁻| ¹⁰⁸Pd| 1+||-| style="text-indent:1em" | ^108mRh| colspan="3" style="text-indent:2em" | 115(18) keV| 6.0(3) min| β⁻| ¹⁰⁸Pd| (5+)||-| ¹⁰⁹Rh| style="text-align:right" | 45| style="text-align:right" | 64| 108.9087496(43)| 80.8(7) s| β⁻| ¹⁰⁹Pd| 7/2+||-| style="text-indent:1em" | ^109mRh| colspan="3" style="text-indent:2em" | 225.873(19) keV| 1.66(4) μs| IT| ¹⁰⁹Pd| 3/2+||-| ¹¹⁰Rh| style="text-align:right" | 45| style="text-align:right" | 65| 109.911080(19)| 3.35(12) s| β⁻| ¹¹⁰Pd| (1+)||-| style="text-indent:1em" | ^110mRh^[2] | colspan="3" style="text-indent:2em" | 220(150)# keV| 28.5(13) s| β⁻| ¹¹⁰Pd| (6+)||-| ¹¹¹Rh| style="text-align:right" | 45| style="text-align:right" | 66| 110.9116432(74)| 11(1) s| β⁻| ¹¹¹Pd| (7/2+)||-| ¹¹²Rh| style="text-align:right" | 45| style="text-align:right" | 67| 111.914405(47)| 3.4(4) s| β⁻| ¹¹²Pd| (1+)||-| style="text-indent:1em" | ^112mRh| colspan="3" style="text-indent:2em" | 340(70) keV| 6.73(15) s| β⁻| ¹¹²Pd| (6+)||-| ¹¹³Rh| style="text-align:right" | 45| style="text-align:right" | 68| 112.9154402(77)| 2.80(12) s| β⁻| ¹¹³Pd| (7/2+)||-| ¹¹⁴Rh| style="text-align:right" | 45| style="text-align:right" | 69| 113.918722(77)| 1.85(5) s| β⁻| ¹¹⁴Pd| 1+| |-| style="text-indent:1em" | ^114mRh^[2] | colspan="3" style="text-indent:2em" | 200(150)# keV| 1.85(5) s| β⁻| ¹¹⁴Pd| (7−)||-| rowspan=2|¹¹⁵Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 70| rowspan=2|114.9203116(79)| rowspan=2|1.03(3) s| β⁻| ¹¹⁵Pd| rowspan=2|(7/2+)| rowspan=2||-| β⁻, n?| ¹¹⁴Pd|-| rowspan=2|¹¹⁶Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 71| rowspan=2|115.924062(79)| rowspan=2|685(39) ms| β⁻ (>97.9%)| ¹¹⁶Pd| rowspan=2|1+| rowspan=2||-| β⁻, n? (<2.1%)| ¹¹⁵Pd|-| rowspan=2 style="text-indent:1em" | ^116mRh^[2] | rowspan=2 colspan="3" style="text-indent:2em" | 200(150)# keV| rowspan=2|570(50) ms| β⁻ (>97.9%)| ¹¹⁶Pd| rowspan=2|(6−)| rowspan=2||-| β⁻, n? (<2.1%)| ¹¹⁵Pd|-| rowspan=2|¹¹⁷Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 72| rowspan=2|116.9260363(95)| rowspan=2|421(30) ms| β⁻| ¹¹⁷Pd| rowspan=2|7/2+#| rowspan=2||-| β⁻, n? (<7.6%)| ¹¹⁵Pd|-| style="text-indent:1em" | ^117mRh| colspan="3" style="text-indent:2em" | 321.2(10) keV| 138(17) ns| IT| ¹¹⁷Rh| 3/2+#||-| rowspan=2|¹¹⁸Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 73| rowspan=2|117.930341(26)| rowspan=2|282(9) ms| β⁻ (96.9%)| ¹¹⁸Pd| rowspan=2|1+#| rowspan=2||-| β⁻, n (3.1%)| ¹¹⁷Pd|-| rowspan=3 style="text-indent:1em" | ^118mRh^[2] | rowspan=3 colspan="3" style="text-indent:2em" | 200(150)# keV| rowspan=3|310(30) ms| β⁻ (96.9%)| ¹¹⁸Pd| rowspan=3|6−#| rowspan=3||-| β⁻, n (3.1%)| ¹¹⁷Pd|-| IT?| ¹¹⁸Rh|-| rowspan=2|¹¹⁹Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 74| rowspan=2|118.932557(10)| rowspan=2|190(6) ms| β⁻ (93.6%)| ¹¹⁹Pd| rowspan=2|7/2+#| rowspan=2||-| β⁻, n (6.4%)| ¹¹⁸Pd|-| rowspan=3| ¹²⁰Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 75| rowspan=3| 119.93707(22)#| rowspan=3| 129.6(42) ms| β⁻| ¹²⁰Pd| rowspan=3| 8−#| rowspan=3||-| β⁻, n (<9.3%)| ¹¹⁹Pd|-| β⁻, 2n?| ¹¹⁸Pd|-| style="text-indent:1em" | ^120mRh| colspan="3" style="text-indent:2em" | 157.2(7) keV| 295(16) ns| IT| ¹²⁰Rh| 6#||-| rowspan=2| ¹²¹Rh| rowspan=2 style="text-align:right" | 45| rowspan=2 style="text-align:right" | 76| rowspan=2| 120.93961(67)| rowspan=2| 74(4) ms| β⁻| ¹²¹Pd| rowspan=2| 7/2+#| rowspan=2||-| β⁻, n (>11%)| ¹²⁰Pd|-| rowspan=3| ¹²²Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 77| rowspan=3| 121.94431(32)#| rowspan=3| 51(6) ms| β⁻| ¹²²Pd| rowspan=3| 7−#| rowspan=3||-| β⁻, n (<3.9%)| ¹²¹Pd|-| β⁻, 2n?| ¹²⁰Pd|-| style="text-indent:1em" | ^122mRh| colspan="3" style="text-indent:2em" | 271.0(7) keV| 830(120) ns| IT| ¹²²Rh| 4+#||-| rowspan=3| ¹²³Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 78| rowspan=3| 122.94719(43)#| rowspan=3| 42(4) ms| β⁻| ¹²³Pd| rowspan=3| 7/2+#| rowspan=3||-| β⁻, n (>24%)| ¹²²Pd|-| β⁻, 2n?| ¹²¹Pd|-| rowspan=3| ¹²⁴Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 79| rowspan=3| 123.95200(43)#| rowspan=3| 30(2) ms| β⁻| ¹²⁴Pd| rowspan=3| 2+#| rowspan=3||-| β⁻, n (<31%)| ¹²³Pd|-| β⁻, 2n?| ¹²²Pd|-| rowspan=3|¹²⁵Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 80| rowspan=3|124.95509(54)#| rowspan=3|26.5(20) ms| β⁻| ¹²⁵Pd| rowspan=3|7/2+#| rowspan=3||-| β⁻, n?| ¹²⁴Pd|-| β⁻, 2n?| ¹²³Pd|-| rowspan=3|¹²⁶Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 81| rowspan=3|125.96006(54)#| rowspan=3|19(3) ms| β⁻| ¹²⁶Pd| rowspan=3|1−#| rowspan=3||-| β⁻, n?| ¹²⁵Pd|-| β⁻, 2n?| ¹²⁴Pd|-| rowspan=3|¹²⁷Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 82| rowspan=3|126.96379(64)#| rowspan=3|28(14) ms| β⁻| ¹²⁷Pd| rowspan=3|7/2+#| rowspan=3||-| β⁻, n?| ¹²⁶Pd|-| β⁻, 2n?| ¹²⁵Pd|-| rowspan=3|¹²⁸Rh| rowspan=3 style="text-align:right" | 45| rowspan=3 style="text-align:right" | 83| rowspan=3|127.97065(32)#| rowspan=3|8# ms
[>550&nbsp;ns]| β⁻?| ¹²⁸Pd| rowspan=3|| rowspan=3||-| β⁻, n?| ¹²⁷Pd|-| β⁻, 2n?| ¹²⁶Pd

References

1. John W. Arblaster . The Discoverers of the Rhodium Isotopes. The thirty-eight known rhodium isotopes found between 1934 and 2010 . Platinum Metals Review . 55 . 2 . April 2011 . 124–134 . 10.1595/147106711X555656. free .
2. Order of ground state and isomer is uncertain.
3. [Fission product]

• Isotope masses from:
  • • Half-life, spin, and isomer data selected from the following sources.