Isotopes of palladium

Isotopes of palladium (₄₆Pd)
γ	–
Standard atomic weight Ar°(Pd)
	106.42±0.01; 106.42±0.01 (abridged);
	view ; talk ; edit ;

Last updated September 07, 2024

Natural palladium (₄₆Pd) is composed of six stable isotopes, ¹⁰²Pd, ¹⁰⁴Pd, ¹⁰⁵Pd, ¹⁰⁶Pd, ¹⁰⁸Pd, and ¹¹⁰Pd, although ¹⁰²Pd and ¹¹⁰Pd are theoretically unstable. The most stable radioisotopes are ¹⁰⁷Pd with a half-life of 6.5 million years, ¹⁰³Pd with a half-life of 17 days, and ¹⁰⁰Pd with a half-life of 3.63 days. Twenty-three other radioisotopes have been characterized with atomic weights ranging from 90.949 u (⁹¹Pd) to 128.96 u (¹²⁹Pd). Most of these have half-lives that are less than 30 minutes except ¹⁰¹Pd (half-life: 8.47 hours), ¹⁰⁹Pd (half-life: 13.7 hours), and ¹¹²Pd (half-life: 21 hours).

Radiogenic ¹⁰⁷Ag is a decay product of ¹⁰⁷Pd and was first discovered in the Santa Clara meteorite of 1978.^[4] The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. ¹⁰⁷Pd versus Ag correlations observed in bodies, which have clearly been melted since accretion of the Solar System, must reflect the presence of short-lived nuclides in the early Solar System.^[5]

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[6] ^{[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]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy^{[n 4]}			Half-life ^[1] ^{[n 4]}	Decay mode ^[1] ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^[1] ^{[n 7]}^{[n 4]}	Normal proportion^[1]	Range of variation
⁹⁰Pd	46	44	89.95737(43)#	10# ms [>400 ns]	β⁺?	⁹⁰Rh	0+
					β⁺, p?	⁸⁹Ru
					2p?	⁸⁸Ru
⁹¹Pd	46	45	90.95044(45)#	32(3) ms	β⁺ (96.9%)	⁹¹Rh	7/2+#
⁹¹Pd	46	45	90.95044(45)#	32(3) ms	β⁺, p (3.1%)	⁹⁰Ru	7/2+#
⁹²Pd	46	46	91.94119(37)	1.06(3) s	β⁺ (98.4%)	⁹²Rh	0+
⁹²Pd	46	46	91.94119(37)	1.06(3) s	β⁺, p (1.6%)	⁹¹Ru	0+
⁹³Pd	46	47	92.93668(40)	1.17(2) s	β⁺ (92.6%)	⁹³Rh	(9/2+)
⁹³Pd	46	47	92.93668(40)	1.17(2) s	β⁺, p (7.4%)	⁹¹Ru	(9/2+)
⁹⁴Pd	46	48	93.9290363(46)	9.1(3) s	β⁺ (>99.87%)	⁹⁴Rh	0+
⁹⁴Pd	46	48	93.9290363(46)	9.1(3) s	β⁺, p (<0.13%)	⁹³Ru	0+
^94m1Pd	4883.1(4) keV			515(1) ns	IT	⁹⁴Pd	(14+)
^94m2Pd	7209.8(8) keV			206(18) ns	IT	⁹⁴Pd	(19−)
⁹⁵Pd	46	49	94.9248885(33)	7.4(4) s	β⁺ (99.77%)	⁹⁵Rh	9/2+#
⁹⁵Pd	46	49	94.9248885(33)	7.4(4) s	β⁺, p (0.23%)	⁹⁵Rh	9/2+#
^95mPd	1875.13(14) keV			13.3(2) s	β⁺ (88%)	⁹⁵Rh	(21/2+)
					IT (11%)	⁹⁵Pd
					β⁺, p (0.71%)	⁹⁴Ru
⁹⁶Pd	46	50	95.9182137(45)	122(2) s	β⁺	⁹⁶Rh	0+
^96mPd	2530.57(23) keV			1.804(7) μs	IT	⁹⁶Pd	8+#
⁹⁷Pd	46	51	96.9164720(52)	3.10(9) min	β⁺	⁹⁷Rh	5/2+#
⁹⁸Pd	46	52	97.9126983(51)	17.7(4) min	β⁺	⁹⁸Rh	0+
⁹⁹Pd	46	53	98.9117731(55)	21.4(2) min	β⁺	⁹⁹Rh	(5/2)+
¹⁰⁰Pd	46	54	99.908520(19)	3.63(9) d	EC	¹⁰⁰Rh	0+
¹⁰¹Pd	46	55	100.9082848(49)	8.47(6) h	β⁺	¹⁰¹Rh	5/2+
¹⁰²Pd	46	56	101.90563229(45)	Observationally Stable ^{[n 8]}			0+	0.0102(1)
¹⁰³Pd	46	57	102.90611107(94)	16.991(19) d	EC	¹⁰³Rh	5/2+
¹⁰⁴Pd	46	58	103.9040304(14)	Stable			0+	0.1114(8)
¹⁰⁵Pd^{[n 9]}	46	59	104.9050795(12)	Stable			5/2+	0.2233(8)
^105mPd	489.1(3) keV			35.5(5) μs	IT	¹⁰⁵Pd	11/2−
¹⁰⁶Pd^{[n 9]}	46	60	105.9034803(12)	Stable			0+	0.2733(3)
¹⁰⁷Pd^{[n 10]}	46	61	106.9051281(13)	6.5(3)×10⁶ y	β⁻	¹⁰⁷Ag	5/2+	trace^{[n 11]}
^107m1Pd	115.74(12) keV			0.85(10) μs	IT	¹⁰⁷Pd	1/2+
^107m2Pd	214.6(3) keV			21.3(5) s	IT	¹⁰⁷Pd	11/2−
¹⁰⁸Pd^{[n 9]}	46	62	107.9038918(12)	Stable			0+	0.2646(9)
¹⁰⁹Pd^{[n 9]}	46	63	108.9059506(12)	13.59(12) h	β⁻	¹⁰⁹Ag	5/2+
^109m1Pd	113.4000(14) keV			380(50) ns	IT	¹⁰⁹Pd	1/2+
^109m2Pd	188.9903(10) keV			4.703(9) min	IT	¹⁰⁹Pd	11/2−
¹¹⁰Pd^{[n 9]}	46	64	109.90517288(66)	Observationally Stable^{[n 12]}			0+	0.1172(9)
¹¹¹Pd	46	65	110.90769036(79)	23.56(9) min	β⁻	¹¹¹Ag	5/2+
^111mPd	172.18(8) keV			5.563(13) h	IT (76.8%)	¹¹¹Pd	11/2−
^111mPd	172.18(8) keV			5.563(13) h	β⁻ (23.2%)	¹¹¹Ag	11/2−
¹¹²Pd	46	66	111.9073306(70)	21.04(17) h	β⁻	¹¹²Ag	0+
¹¹³Pd	46	67	112.9102619(75)	93(5) s	β⁻	¹¹³Ag	(5/2+)
^113mPd	81.1(3) keV			0.3(1) s	IT	¹¹³Pd	(9/2−)
¹¹⁴Pd	46	68	113.9103694(75)	2.42(6) min	β⁻	¹¹⁴Ag	0+
¹¹⁵Pd	46	69	114.9136650(19)^[7]	25(2) s	β⁻	¹¹⁵Ag	(1/2)+
^115mPd	86.8(29) keV^[7]			50(3) s	β⁻ (92.0%)	¹¹⁵Ag	(7/2−)
^115mPd	86.8(29) keV^[7]			50(3) s	IT (8.0%)	¹¹⁵Pd	(7/2−)
¹¹⁶Pd	46	70	115.9142979(77)	11.8(4) s	β⁻	¹¹⁶Ag	0+
¹¹⁷Pd	46	71	116.9179556(78)	4.3(3) s	β⁻	¹¹⁷Ag	(3/2+)
^117mPd	203.3(3) keV			19.1(7) ms	IT	¹¹⁷Pd	(9/2−)
¹¹⁸Pd	46	72	117.9190673(27)	1.9(1) s	β⁻	¹¹⁸Ag	0+
¹¹⁹Pd	46	73	118.9231238(45)^[7]	0.88(2) s	β⁻	¹¹⁹Ag	1/2+, 3/2+^[8]
¹¹⁹Pd	46	73	118.9231238(45)^[7]	0.88(2) s	β⁻, n?	¹¹⁸Ag	1/2+, 3/2+^[8]
^119mPd^[7]	199.1(30) keV			0.85(1) s	IT	¹¹⁹Pd	(11/2−)^[8]
¹²⁰Pd	46	74	119.9245517(25)	492(33) ms	β⁻ (>99.3%)	¹²⁰Ag	0+
¹²⁰Pd	46	74	119.9245517(25)	492(33) ms	β⁻, n (<0.7%)	¹¹⁹Ag	0+
¹²¹Pd	46	75	120.9289513(40)^[7]	290(1) ms	β⁻ (>99.2%)	¹²¹Ag	3/2+#
¹²¹Pd	46	75	120.9289513(40)^[7]	290(1) ms	β⁻, n (<0.8%)	¹²⁰Ag	3/2+#
^121m1Pd	135.5(5) keV			460(90) ns	IT	¹²¹Pd	7/2+#
^121m2Pd	160(14) keV			460(90) ns	IT	¹²¹Pd	11/2−#
¹²²Pd	46	76	121.930632(21)	193(5) ms	β⁻	¹²²Ag	0+
¹²²Pd	46	76	121.930632(21)	193(5) ms	β⁻, n (<2.5%)	¹²¹Ag	0+
¹²³Pd	46	77	122.93513(85)	108(1) ms	β⁻ (90%)	¹²³Ag	3/2+#
¹²³Pd	46	77	122.93513(85)	108(1) ms	β⁻, n (10%)	¹²²Ag	3/2+#
^123mPd	100(50)# keV			100# ms	β⁻	¹²³Ag	11/2−#
^123mPd	100(50)# keV			100# ms	IT?	¹²³Pd	11/2−#
¹²⁴Pd	46	78	123.93731(32)#	88(15) ms	β⁻ (83%)	¹²⁴Ag	0+
¹²⁴Pd	46	78	123.93731(32)#	88(15) ms	β⁻, n (17%)	¹²³Ag	0+
^124mPd	1000(800)# keV			>20 μs	IT	¹²⁴Pd	11/2−#
¹²⁵Pd	46	79	124.94207(43)#	60(6) ms	β⁻ (88%)	¹²⁵Ag	3/2+#
¹²⁵Pd	46	79	124.94207(43)#	60(6) ms	β⁻, n (12%)	¹²⁴Ag	3/2+#
^125m1Pd	100(50)# keV			50# ms	β⁻	¹²⁵Ag	11/2−#
^125m1Pd	100(50)# keV			50# ms	IT?	¹²⁵Pd	11/2−#
^125m2Pd	1805.23(18) keV			144(4) ns	IT	¹²⁵Pd	(23/2+)
¹²⁶Pd	46	80	125.94440(43)#	48.6(8) ms	β⁻ (78%)	¹²⁶Ag	0+
¹²⁶Pd	46	80	125.94440(43)#	48.6(8) ms	β⁻, n (22%)	¹²⁵Ag	0+
^126m1Pd	2023.5(7) keV			330(40) ns	IT	¹²⁶Pd	(5−)
^126m2Pd	2109.7(9) keV			440(30) ns	IT	¹²⁶Pd	(7−)
^126m3Pd	2406.0(10) keV			23.0(8) ms	β⁻ (72%)	¹²⁶Ag	(10+)
^126m3Pd	2406.0(10) keV			23.0(8) ms	IT (28%)	¹²⁶Pd	(10+)
¹²⁷Pd	46	81	126.94931(54)#	38(2) ms	β⁻ (>81%)	¹²⁷Ag	11/2−#
					β⁻, n (<19%)	¹²⁶Ag
					β⁻, 2n?	¹²⁵Ag
^127mPd	1717.91(23) keV			39(6) μs	IT	¹²⁷Pd	(19/2+)
¹²⁸Pd	46	82	127.95235(54)#	35(3) ms	β⁻	¹²⁸Ag	0+
¹²⁸Pd	46	82	127.95235(54)#	35(3) ms	β⁻, n?	¹²⁷Ag	0+
^128mPd	2151.0(10) keV			5.8(8) μs	IT	¹²⁸Pd	(8+)
¹²⁹Pd	46	83	128.95933(64)#	31(7) ms	β⁻	¹²⁹Ag	7/2−#
					β⁻, n?	¹²⁸Ag
					β⁻, 2n?	¹²⁷Ag
¹³⁰Pd	46	84	129.96486(32)#	27# ms [>550 ns]	β⁻	¹³⁰Ag	0+
					β⁻, n?	¹²⁹Ag
					β⁻, 2n?	¹²⁸Ag
¹³¹Pd	46	85	130.97237(32)#	20# ms [>550 ns]	β⁻	¹³¹Ag	7/2−#
					β⁻, n?	¹³⁰Ag
					β⁻, 2n?	¹²⁹Ag
This table header & footer: view

↑ ^mPd – 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
p: Proton emission
↑ Bold symbol as daughter – Daughter product is stable.
↑ ( ) spin value – Indicates spin with weak assignment arguments.
↑ Believed to decay by β⁺β⁺ to ¹⁰²Ru with a half-life over 7.6×10¹⁸ y
1 2 3 4 5 Fission product
↑ Long-lived fission product
↑ Cosmogenic nuclide, also found as nuclear contamination
↑ Believed to decay by β⁻β⁻ to ¹¹⁰Cd with a half-life over 2.9×10²⁰ years

Palladium-103

Palladium-103 is a radioisotope of the element palladium that has uses in radiation therapy for prostate cancer and uveal melanoma. Palladium-103 may be created from palladium-102 or from rhodium-103 using a cyclotron. Palladium-103 has a half-life of 16.99^[9] days and decays by electron capture to rhodium-103, emitting characteristic x-rays with 21 keV of energy.

Palladium-107

Long-lived fission products
v
t
e
Nuclide	t_1⁄2	Yield	Q ^{[a 1]}	βγ
	(Ma)	(%)^{[a 2]}	(keV)
⁹⁹Tc	0.211	6.1385	294	β
¹²⁶Sn	0.230	0.1084	4050^{[a 3]}	βγ
⁷⁹Se	0.327	0.0447	151	β
¹³⁵Cs	1.33	6.9110^{[a 4]}	269	β
⁹³Zr	1.53	5.4575	91	βγ
¹⁰⁷Pd	6.5	1.2499	33	β
¹²⁹I	15.7	0.8410	194	βγ
↑ Decay energy is split among β, neutrino, and γ if any. ↑ Per 65 thermal neutron fissions of ²³⁵U and 35 of ²³⁹Pu. ↑ Has decay energy 380 keV, but its decay product ¹²⁶Sb has decay energy 3.67 MeV. ↑ Lower in thermal reactors because ¹³⁵Xe, its predecessor, readily absorbs neutrons.

Palladium-107 is the second-longest lived (half-life of 6.5 million years^[9]) and least radioactive (decay energy only 33 keV, specific activity 5×10⁻⁵ Ci/g) of the 7 long-lived fission products. It undergoes pure beta decay (without gamma radiation) to ¹⁰⁷Ag, which is stable.

Its yield from thermal neutron fission of uranium-235 is 0.14% per fission,^[10] only 1/4 that of iodine-129, and only 1/40 those of ⁹⁹Tc, ⁹³Zr, and ¹³⁵Cs. Yield from ²³³U is slightly lower, but yield from ²³⁹Pu is much higher, 3.2%.^[10] Fast fission or fission of some heavier actinides ^[which?] will produce palladium-107 at higher yields.

One source^[11] estimates that palladium produced from fission contains the isotopes ¹⁰⁴Pd (16.9%),¹⁰⁵Pd (29.3%), ¹⁰⁶Pd (21.3%), ¹⁰⁷Pd (17%), ¹⁰⁸Pd (11.7%) and ¹¹⁰Pd (3.8%). According to another source, the proportion of ¹⁰⁷Pd is 9.2% for palladium from thermal neutron fission of ²³⁵U, 11.8% for ²³³U, and 20.4% for ²³⁹Pu (and the ²³⁹Pu yield of palladium is about 10 times that of ²³⁵U).

Because of this dilution and because ¹⁰⁵Pd has 11 times the neutron absorption cross section, ¹⁰⁷Pd is not amenable to disposal by nuclear transmutation. However, as a noble metal, palladium is not as mobile in the environment as iodine or technetium.

Related Research Articles

Protactinium (₉₁Pa) has no stable isotopes. The four naturally occurring isotopes allow a standard atomic weight to be given.

There are seven stable isotopes of mercury (₈₀Hg) with ²⁰²Hg being the most abundant (29.86%). The longest-lived radioisotopes are ¹⁹⁴Hg with a half-life of 444 years, and ²⁰³Hg with a half-life of 46.612 days. Most of the remaining 40 radioisotopes have half-lives that are less than a day. ¹⁹⁹Hg and ²⁰¹Hg are the most often studied NMR-active nuclei, having spin quantum numbers of 1/2 and 3/2 respectively. All isotopes of mercury are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. These isotopes are predicted to undergo either alpha decay or double beta decay.

Naturally occurring platinum (₇₈Pt) consists of five stable isotopes (¹⁹²Pt, ¹⁹⁴Pt, ¹⁹⁵Pt, ¹⁹⁶Pt, ¹⁹⁸Pt) and one very long-lived (half-life 4.83×10¹¹ years) radioisotope (¹⁹⁰Pt). There are also 34 known synthetic radioisotopes, the longest-lived of which is ¹⁹³Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.

Naturally occurring samarium (₆₂Sm) is composed of five stable isotopes, ¹⁴⁴Sm, ¹⁴⁹Sm, ¹⁵⁰Sm, ¹⁵²Sm and ¹⁵⁴Sm, and two extremely long-lived radioisotopes, ¹⁴⁷Sm and ¹⁴⁸Sm, with ¹⁵²Sm being the most abundant. ¹⁴⁶Sm is also fairly long-lived, but is not long-lived enough to have survived in significant quantities from the formation of the Solar System on Earth, although it remains useful in radiometric dating in the Solar System as an extinct radionuclide. It is the longest-lived nuclide that has not yet been confirmed to be primordial.

Naturally occurring neodymium (₆₀Nd) is composed of 5 stable isotopes, ¹⁴²Nd, ¹⁴³Nd, ¹⁴⁵Nd, ¹⁴⁶Nd and ¹⁴⁸Nd, with ¹⁴²Nd being the most abundant (27.2% natural abundance), and 2 long-lived radioisotopes, ¹⁴⁴Nd and ¹⁵⁰Nd. In all, 33 radioisotopes of neodymium have been characterized up to now, with the most stable being naturally occurring isotopes ¹⁴⁴Nd (alpha decay, a half-life (t_1/2) of 2.29×10¹⁵ years) and ¹⁵⁰Nd (double beta decay, t_1/2 of 7×10¹⁸ years), and for practical purposes they can be considered to be stable as well. All of the remaining radioactive isotopes have half-lives that are less than 12 days, and the majority of these have half-lives that are less than 70 seconds; the most stable artificial isotope is ¹⁴⁷Nd with a half-life of 10.98 days. This element also has 13 known meta states with the most stable being ^139mNd (t_1/2 5.5 hours), ^135mNd (t_1/2 5.5 minutes) and ^133m1Nd (t_1/2 ~70 seconds).

Naturally occurring cerium (₅₈Ce) is composed of 4 stable isotopes: ¹³⁶Ce, ¹³⁸Ce, ¹⁴⁰Ce, and ¹⁴²Ce, with ¹⁴⁰Ce being the most abundant and the only one theoretically stable; ¹³⁶Ce, ¹³⁸Ce, and ¹⁴²Ce are predicted to undergo double beta decay but this process has never been observed. There are 35 radioisotopes that have been characterized, with the most stable being ¹⁴⁴Ce, with a half-life of 284.893 days; ¹³⁹Ce, with a half-life of 137.640 days and ¹⁴¹Ce, with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 10 meta states.

Naturally occurring barium (₅₆Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001. This nuclide decays by double electron capture (absorbing two electrons and emitting two neutrinos), with a half-life of (0.5–2.7)×10²¹ years (about 10¹¹ times the age of the universe).

There are 39 known isotopes and 17 nuclear isomers of tellurium (₅₂Te), with atomic masses that range from 104 to 142. These are listed in the table below.

Tin (₅₀Sn) is the element with the greatest number of stable isotopes. This is probably related to the fact that 50 is a "magic number" of protons. In addition, twenty-nine unstable tin isotopes are known, including tin-100 (¹⁰⁰Sn) and tin-132 (¹³²Sn), which are both "doubly magic". The longest-lived tin radioisotope is tin-126 (¹²⁶Sn), with a half-life of 230,000 years. The other 28 radioisotopes have half-lives of less than a year.

Indium (₄₉In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (¹¹⁵In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×10¹⁴ years, much longer than the currently accepted age of the Universe.

Naturally occurring silver (₄₇Ag) is composed of the two stable isotopes ¹⁰⁷Ag and ¹⁰⁹Ag in almost equal proportions, with ¹⁰⁷Ag being slightly more abundant. Notably, silver is the only element with all stable istopes having nuclear spins of 1/2. Thus both ¹⁰⁷Ag and ¹⁰⁹Ag nuclei produce narrow lines in nuclear magnetic resonance spectra.

Naturally occurring cadmium (₄₈Cd) is composed of 8 isotopes. For two of them, natural radioactivity was observed, and three others are predicted to be radioactive but their decays have not been observed, due to extremely long half-lives. The two natural radioactive isotopes are ¹¹³Cd (beta decay, half-life is 8.04 × 10¹⁵ years) and ¹¹⁶Cd (two-neutrino double beta decay, half-life is 2.8 × 10¹⁹ years). The other three are ¹⁰⁶Cd, ¹⁰⁸Cd (double electron capture), and ¹¹⁴Cd (double beta decay); only lower limits on their half-life times have been set. Three isotopes—¹¹⁰Cd, ¹¹¹Cd, and ¹¹²Cd—are theoretically stable. Among the isotopes absent in natural cadmium, the most long-lived are ¹⁰⁹Cd with a half-life of 462.6 days, and ¹¹⁵Cd with a half-life of 53.46 hours. All of the remaining radioactive isotopes have half-lives that are less than 2.5 hours and the majority of these have half-lives that are less than 5 minutes. This element also has 12 known meta states, with the most stable being ^113mCd (t_1/2 14.1 years), ^115mCd (t_1/2 44.6 days) and ^117mCd (t_1/2 3.36 hours).

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh. 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 and ¹⁰⁵Rh. 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.

Naturally occurring ruthenium (₄₄Ru) is composed of seven stable isotopes. Additionally, 27 radioactive isotopes have been discovered. Of these radioisotopes, the most stable are ¹⁰⁶Ru, with a half-life of 373.59 days; ¹⁰³Ru, with a half-life of 39.26 days and ⁹⁷Ru, with a half-life of 2.9 days.

Molybdenum (₄₂Mo) has 39 known isotopes, ranging in atomic mass from 81 to 119, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. All unstable isotopes of molybdenum decay into isotopes of zirconium, niobium, technetium, and ruthenium.

Naturally occurring zirconium (₄₀Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (⁹⁶Zr), a primordial nuclide that decays via double beta decay with an observed half-life of 2.0×10¹⁹ years; it can also undergo single beta decay, which is not yet observed, but the theoretically predicted value of t_1/2 is 2.4×10²⁰ years. The second most stable radioisotope is ⁹³Zr, which has a half-life of 1.53 million years. Thirty other radioisotopes have been observed. All have half-lives less than a day except for ⁹⁵Zr (64.02 days), ⁸⁸Zr (83.4 days), and ⁸⁹Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than ⁹²Zr, and the primary mode for heavier isotopes is beta decay.

The alkaline earth metal strontium (₃₈Sr) has four stable, naturally occurring isotopes: ⁸⁴Sr (0.56%), ⁸⁶Sr (9.86%), ⁸⁷Sr (7.0%) and ⁸⁸Sr (82.58%). Its standard atomic weight is 87.62(1).

Selenium (₃₄Se) has six natural isotopes that occur in significant quantities, along with the trace isotope ⁷⁹Se, which occurs in minute quantities in uranium ores. Five of these isotopes are stable: ⁷⁴Se, ⁷⁶Se, ⁷⁷Se, ⁷⁸Se, and ⁸⁰Se. The last three also occur as fission products, along with ⁷⁹Se, which has a half-life of 327,000 years, and ⁸²Se, which has a very long half-life (~10²⁰ years, decaying via double beta decay to ⁸²Kr) and for practical purposes can be considered to be stable. There are 23 other unstable isotopes that have been characterized, the longest-lived being ⁷⁹Se with a half-life 327,000 years, ⁷⁵Se with a half-life of 120 days, and ⁷²Se with a half-life of 8.40 days. Of the other isotopes, ⁷³Se has the longest half-life, 7.15 hours; most others have half-lives not exceeding 38 seconds.

Neptunium (₉₃Np) is usually considered an artificial element, although trace quantities are found in nature, so a standard atomic weight cannot be given. Like all trace or artificial elements, it has no stable isotopes. The first isotope to be synthesized and identified was ²³⁹Np in 1940, produced by bombarding ²³⁸
U with neutrons to produce ²³⁹
U, which then underwent beta decay to ²³⁹
Np.

Plutonium (₉₄Pu) is an artificial element, except for trace quantities resulting from neutron capture by uranium, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized being plutonium-238 in 1940. Twenty plutonium radioisotopes have been characterized. The most stable are plutonium-244 with a half-life of 80.8 million years; plutonium-242 with a half-life of 373,300 years; and plutonium-239 with a half-life of 24,110 years; and plutonium-240 with a half-life of 6,560 years. This element also has eight meta states; all have half-lives of less than one second.

References

Patent application for Palladium-103 implantable radiation-delivery device ^{[ permanent dead link ]} (accessed 12/7/05)

1 2 3 4 5 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.
↑ "Standard Atomic Weights: Palladium". CIAAW. 1979.
↑ 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.
↑ W. R. Kelly; G. J. Wasserburg (1978). "Evidence for the existence of ¹⁰⁷Pd in the early solar system". Geophysical Research Letters . 5 (12): 1079–1082. Bibcode:1978GeoRL...5.1079K. doi:10.1029/GL005i012p01079.
↑ J. H. Chen; G. J. Wasserburg (1990). "The isotopic composition of Ag in meteorites and the presence of ¹⁰⁷Pd in protoplanets". Geochimica et Cosmochimica Acta . 54 (6): 1729–1743. Bibcode:1990GeCoA..54.1729C. doi:10.1016/0016-7037(90)90404-9.
↑ 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.
1 2 3 4 5 Jaries, A.; Stryjczyk, M.; Kankainen, A.; Ayoubi, L. Al; Beliuskina, O.; Canete, L.; de Groote, R. P.; Delafosse, C.; Delahaye, P.; Eronen, T.; Flayol, M.; Ge, Z.; Geldhof, S.; Gins, W.; Hukkanen, M.; Imgram, P.; Kahl, D.; Kostensalo, J.; Kujanpää, S.; Kumar, D.; Moore, I. D.; Mougeot, M.; Nesterenko, D. A.; Nikas, S.; Patel, D.; Penttilä, H.; Pitman-Weymouth, D.; Pohjalainen, I.; Raggio, A.; Ramalho, M.; Reponen, M.; Rinta-Antila, S.; de Roubin, A.; Ruotsalainen, J.; Srivastava, P. C.; Suhonen, J.; Vilen, M.; Virtanen, V.; Zadvornaya, A. "Physical Review C - Accepted Paper: Isomeric states of fission fragments explored via Penning trap mass spectrometry at IGISOL". journals.aps.org. arXiv: 2403.04710 .
1 2 Kurpeta, J.; Abramuk, A.; Rząca-Urban, T.; Urban, W.; Canete, L.; Eronen, T.; Geldhof, S.; Gierlik, M.; Greene, J. P.; Jokinen, A.; Kankainen, A.; Moore, I. D.; Nesterenko, D. A.; Penttilä, H.; Pohjalainen, I.; Reponen, M.; Rinta-Antila, S.; de Roubin, A.; Simpson, G. S.; Smith, A. G.; Vilén, M. (14 March 2022). "β - and γ -spectroscopy study of Pd 119 and Ag 119". Physical Review C. 105 (3). doi:10.1103/PhysRevC.105.034316.
1 2 Winter, Mark. "Isotopes of palladium". WebElements. The University of Sheffield and WebElements Ltd, UK. Retrieved 4 March 2013.
1 2 Weller, A.; Ramaker, T.; Stäger, F.; Blenke, T.; Raiwa, M.; Chyzhevskyi, I.; Kirieiev, S.; Dubchak, S.; Steinhauser, G. (2021). "Detection of the Fission Product Palladium-107 in a Pond Sediment Sample from Chernobyl". Environmental Science & Technology Letters. 8 (8): 656–661. Bibcode:2021EnSTL...8..656W. doi:10.1021/acs.estlett.1c00420.
↑ R. P. Bush (1991). "Recovery of Platinum Group Metals from High Level Radioactive Waste" (PDF). Platinum Metals Review. 35 (4): 202–208. doi:10.1595/003214091X354202208. Archived from the original (PDF) on 2015-09-24. Retrieved 2011-04-02.

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
Isotopic compositions and standard atomic masses from:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry . 75 (6): 683–800. doi: 10.1351/pac200375060683 .
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry . 78 (11): 2051–2066. doi: 10.1351/pac200678112051 .

"News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
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.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[6] Pd – Excited nuclear isomer.

[8] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-9] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[TNN-10] 1 2 3 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[11] Modes of decay:
EC: Electron capture
IT: Isomeric transition
p: Proton emission

[12] Bold symbol as daughter – Daughter product is stable.

[13] ( ) spin value – Indicates spin with weak assignment arguments.

[14] Believed to decay by β⁺β⁺ to ¹⁰²Ru with a half-life over 7.6×10¹⁸ y

[FP-15] 1 2 3 4 5 Fission product

[16] Long-lived fission product

[17] Cosmogenic nuclide, also found as nuclear contamination

[18] Believed to decay by β⁻β⁻ to ¹¹⁰Cd with a half-life over 2.9×10²⁰ years

[22] Decay energy is split among β, neutrino, and γ if any.

[23] Per 65 thermal neutron fissions of ²³⁵U and 35 of ²³⁹Pu.

[24] Has decay energy 380 keV, but its decay product ¹²⁶Sb has decay energy 3.67 MeV.

[25] Lower in thermal reactors because ¹³⁵Xe, its predecessor, readily absorbs neutrons.

[NUBASE2020-1] 1 2 3 4 5 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: Palladium". CIAAW. 1979.

[CIAAW2021-3] 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] W. R. Kelly; G. J. Wasserburg (1978). "Evidence for the existence of ¹⁰⁷Pd in the early solar system". Geophysical Research Letters . 5 (12): 1079–1082. Bibcode:1978GeoRL...5.1079K. doi:10.1029/GL005i012p01079.

[5] J. H. Chen; G. J. Wasserburg (1990). "The isotopic composition of Ag in meteorites and the presence of ¹⁰⁷Pd in protoplanets". Geochimica et Cosmochimica Acta . 54 (6): 1729–1743. Bibcode:1990GeCoA..54.1729C. doi:10.1016/0016-7037(90)90404-9.

[AME2020_II-7] 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.

[jaries2024-19] 1 2 3 4 5 Jaries, A.; Stryjczyk, M.; Kankainen, A.; Ayoubi, L. Al; Beliuskina, O.; Canete, L.; de Groote, R. P.; Delafosse, C.; Delahaye, P.; Eronen, T.; Flayol, M.; Ge, Z.; Geldhof, S.; Gins, W.; Hukkanen, M.; Imgram, P.; Kahl, D.; Kostensalo, J.; Kujanpää, S.; Kumar, D.; Moore, I. D.; Mougeot, M.; Nesterenko, D. A.; Nikas, S.; Patel, D.; Penttilä, H.; Pitman-Weymouth, D.; Pohjalainen, I.; Raggio, A.; Ramalho, M.; Reponen, M.; Rinta-Antila, S.; de Roubin, A.; Ruotsalainen, J.; Srivastava, P. C.; Suhonen, J.; Vilen, M.; Virtanen, V.; Zadvornaya, A. "Physical Review C - Accepted Paper: Isomeric states of fission fragments explored via Penning trap mass spectrometry at IGISOL". journals.aps.org. arXiv: 2403.04710 .

[kurpeta2022-20] 1 2 Kurpeta, J.; Abramuk, A.; Rząca-Urban, T.; Urban, W.; Canete, L.; Eronen, T.; Geldhof, S.; Gierlik, M.; Greene, J. P.; Jokinen, A.; Kankainen, A.; Moore, I. D.; Nesterenko, D. A.; Penttilä, H.; Pohjalainen, I.; Reponen, M.; Rinta-Antila, S.; de Roubin, A.; Simpson, G. S.; Smith, A. G.; Vilén, M. (14 March 2022). "β - and γ -spectroscopy study of Pd 119 and Ag 119". Physical Review C. 105 (3). doi:10.1103/PhysRevC.105.034316.

[webelements-21] 1 2 Winter, Mark. "Isotopes of palladium". WebElements. The University of Sheffield and WebElements Ltd, UK. Retrieved 4 March 2013.

[Pd107-2021-26] 1 2 Weller, A.; Ramaker, T.; Stäger, F.; Blenke, T.; Raiwa, M.; Chyzhevskyi, I.; Kirieiev, S.; Dubchak, S.; Steinhauser, G. (2021). "Detection of the Fission Product Palladium-107 in a Pond Sediment Sample from Chernobyl". Environmental Science & Technology Letters. 8 (8): 656–661. Bibcode:2021EnSTL...8..656W. doi:10.1021/acs.estlett.1c00420.

[27] R. P. Bush (1991). "Recovery of Platinum Group Metals from High Level Radioactive Waste" (PDF). Platinum Metals Review. 35 (4): 202–208. doi:10.1595/003214091X354202208. Archived from the original (PDF) on 2015-09-24. Retrieved 2011-04-02.

[1]

[2]

[3]

[4]

[5]

[n 1]

[6]

[n 2]

[n 3]

[n 4]

[n 5]

[n 6]

[n 7]

[n 8]

[n 9]

[n 10]

[n 11]

[n 12]

[7]

[8]

[9]

[a 1]

[a 2]

[a 3]

[a 4]

[10]

[11]