Isotopes of rhodium

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh. 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			Decay
Isotope	abundance	half-life (t_1/2)	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
^101mRh	synth	4.343 d	IT	¹⁰¹Rh
¹⁰²Rh	synth	207 d	β⁺	¹⁰²Ru
¹⁰²Rh	synth	207 d	β⁻	¹⁰²Pd
^102mRh	synth	3.742 y	β⁺	¹⁰²Ru
^102mRh	synth	3.742 y	IT	¹⁰²Rh
¹⁰³Rh	100%	stable
¹⁰⁵Rh	synth	35.34 h	β⁻	¹⁰⁵Pd

Standard atomic weight A_r°(Rh)

102.90549±0.00002
102.91±0.01 (abridged)

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	Z	N	Isotopic mass (Da)	Half-life	Decay mode	Daughter isotope	Spin and parity	Isotopic abundance
Nuclide	Excitation energy			Half-life	Decay mode	Daughter isotope	Spin and parity	Isotopic abundance
⁹⁰Rh	45	45	89.94457(22)#	29(3) ms	β⁺	⁹⁰Ru	(0+)
⁹⁰Rh	45	45	89.94457(22)#	29(3) ms	β⁺, p? (<0.7%)	⁸⁹Tc	(0+)
^90mRh	0(500)# keV			0.56(2) s	β⁺ (90.4%)	⁹⁰Ru	(7+)
^90mRh	0(500)# keV			0.56(2) s	β⁺, p (9.6%)	⁸⁹Tc	(7+)
⁹¹Rh	45	46	90.93712(32)#	1.47(22) s	β⁺ (98.7%)	⁹¹Ru	(9/2+)
⁹¹Rh	45	46	90.93712(32)#	1.47(22) s	β⁺, p (1.3%)	⁹⁰Tc	(9/2+)
^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+)
⁹²Rh	45	47	91.9323677(47)	5.61(8) s	β⁺, p (2.05%)	⁹¹Tc	(6+)
^92m1Rh	50(100)# keV			3.18(22) s	β⁺ (98.3%)	⁹²Ru	(2+)
^92m1Rh	50(100)# keV			3.18(22) s	β⁺, p (1.7%)	⁹¹Tc	(2+)
^92m2Rh	105(100)# keV			232(15) ns	IT	⁹²Rh	(4+)
⁹³Rh	45	48	92.9259128(28)	13.9(16) s	β⁺	⁹³Ru	9/2+#
^93mRh	267(48) keV						(1/2−)
⁹⁴Rh	45	49	93.9217305(36)	70.6(6) s	β⁺ (98.2%)	⁹⁴Ru	(4+)
⁹⁴Rh	45	49	93.9217305(36)	70.6(6) s	β⁺, p (1.8%)	⁹³Tc	(4+)
^94m1Rh	54.60(20)# keV			480(30) ns	IT	⁹⁴Rh	(2+)
^94m2Rh	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)−
^95mRh	543.3(3) keV			1.96(4) min	β⁺ (12%)	⁹⁵Ru	(1/2)−
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+
^96mRh	51.98(9) keV			1.51(2) min	β⁺ (40%)	⁹⁶Ru	3+
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−
^97mRh	258.76(18) keV			46.2(16) min	IT (5.6%)	⁹⁷Rh	1/2−
⁹⁸Rh	45	53	97.910708(13)	8.72(12) min	β⁺	⁹⁸Ru	(2)+
^98mRh	56.3(10) keV			3.6(2) min	IT (89%)	⁹⁸Rh	(5+)
^98mRh	56.3(10) keV			3.6(2) min	β⁺ (11%)	⁹⁸Ru	(5+)
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+
^99mRh	64.4(5) keV			4.7(1) h	IT?	⁹⁹Rh	9/2+
¹⁰⁰Rh	45	55	99.908114(19)	20.8(1) h	EC (95.1%)	¹⁰⁰Ru	1−
¹⁰⁰Rh	45	55	99.908114(19)	20.8(1) h	β⁺ (4.9%)	¹⁰⁰Ru	1−
^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+)
^100m2Rh	107.6(2) keV			4.6(2) min	β⁺ (1.7%)	¹⁰⁰Ru	(5+)
^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+
^101mRh	157.32(3) keV			4.343(10) d	IT (7.20%)	¹⁰¹Rh	9/2+
¹⁰²Rh	45	57	101.9068343(69)	207.0(15) d	β⁺ (78%)	¹⁰²Ru	2−
¹⁰²Rh	45	57	101.9068343(69)	207.0(15) d	β⁻ (22%)	¹⁰²Pd	2−
^102mRh	140.73(9) keV			3.742(10) y	β⁺ (99.77%)	¹⁰²Ru	6+
^102mRh	140.73(9) keV			3.742(10) y	IT (0.233%)	¹⁰²Rh	6+
¹⁰³Rh	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+
¹⁰⁴Rh	45	59	103.9066453(25)	42.3(4) s	β⁺ (0.45%)	¹⁰⁴Ru	1+
^104mRh	128.9679(5) keV			4.34(3) min	IT (99.87%)	¹⁰⁴Rh	5+
^104mRh	128.9679(5) keV			4.34(3) min	β⁻ (0.13%)	¹⁰⁴Pd	5+
¹⁰⁵Rh	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	¹⁰⁹Rh	3/2+
¹¹⁰Rh	45	65	109.911080(19)	3.35(12) s	β⁻	¹¹⁰Pd	(1+)
^110mRh	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	200(150)# keV			1.85(5) s	β⁻	¹¹⁴Pd	(7−)
¹¹⁵Rh	45	70	114.9203116(79)	1.03(3) s	β⁻	¹¹⁵Pd	(7/2+)
¹¹⁵Rh	45	70	114.9203116(79)	1.03(3) s	β⁻, n?	¹¹⁴Pd	(7/2+)
¹¹⁶Rh	45	71	115.924062(79)	685(39) ms	β⁻ (>97.9%)	¹¹⁶Pd	1+
¹¹⁶Rh	45	71	115.924062(79)	685(39) ms	β⁻, n? (<2.1%)	¹¹⁵Pd	1+
^116mRh	200(150)# keV			570(50) ms	β⁻ (>97.9%)	¹¹⁶Pd	(6−)
^116mRh	200(150)# keV			570(50) ms	β⁻, n? (<2.1%)	¹¹⁵Pd	(6−)
¹¹⁷Rh	45	72	116.9260363(95)	421(30) ms	β⁻	¹¹⁷Pd	7/2+#
¹¹⁷Rh	45	72	116.9260363(95)	421(30) ms	β⁻, n? (<7.6%)	¹¹⁶Pd	7/2+#
^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+#
¹¹⁸Rh	45	73	117.930341(26)	282(9) ms	β⁻, n (3.1%)	¹¹⁷Pd	1+#
^118mRh	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+#
¹¹⁹Rh	45	74	118.932557(10)	190(6) ms	β⁻, n (6.4%)	¹¹⁸Pd	7/2+#
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+#
¹²¹Rh	45	76	120.93961(67)	74(4) ms	β⁻, n (>11%)	¹²⁰Pd	7/2+#
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

^mRh – 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).
# – 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.
Order of ground state and isomer is uncertain.
Fission product

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

List of isotopes

See also