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 4.07 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 ranging from ⁸⁹Rh to ¹²²Rh - these have half-lives that are less than an hour except ¹⁰⁰Rh (20.8 hours) and ¹⁰⁵Rh (35.34 hours). There are also numerous meta states with the most stable being ^102mRh with a half-life of 3.74 years and ^101mRh 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 100Rh synth 20.8 h β+ 100Ru 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 35.34 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 to ruthenium isotopes, and the primary mode after is beta emission to palladium isotopes. Mass numbers 102 and 104 are capable of decay in either sense.

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[n 9]	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[n 9]	129.742(4) keV			42.8(3) s	IT	105Rh	1/2−
106Rh[n 9]	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	109Rh	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%)	116Pd
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

See also

Daughter products other than rhodium

• Isotopes of palladium
• Isotopes of ruthenium
• Isotopes of technetium