Isotopes of rhodium

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh.^[4] 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.

Isotopes of rhodium (₄₅Rh)

Main isotopes[1] Decay abun­dance half-life (t1/2) mode pro­duct 99Rh synth 16.1 d β+ 99Ru 101Rh synth 4.07 y ε 101Ru 101mRh synth 4.343 d ε 101Ru IT 101Rh 102Rh synth 207 d β+ 102Ru β− 102Pd 102mRh synth 3.742 y β+ 102Ru IT 102Rh 103Rh 100% stable 105Rh synth 35.341 h β− 105Pd
Standard atomic weight Ar°(Rh)
	102.90549±0.00002[2] 102.91±0.01 (abridged)[3]
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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

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

1. ^mRh – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
5. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   n:	Neutron emission
   p:	Proton emission

6. Bold symbol as daughter – Daughter product is stable.
7. ( ) spin value – Indicates spin with weak assignment arguments.
8. Order of ground state and isomer is uncertain.
9. Fission product

References

1. Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
2. "Standard Atomic Weights: Rhodium". CIAAW. 2017.
3. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
4. John W. Arblaster (April 2011). "The Discoverers of the Rhodium Isotopes. The thirty-eight known rhodium isotopes found between 1934 and 2010". Platinum Metals Review. 55 (2): 124–134. doi:10.1595/147106711X555656.
5. Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.