Isotopes of palladium

Last updated
Isotopes of palladium  (46Pd)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
100Pd synth 3.63 d ε 100Rh
γ –
102Pd1.02% stable
103Pdsynth16.991 dε 103Rh
104Pd11.1%stable
105Pd22.3%stable
106Pd27.3%stable
107Pd trace 6.5×106 y β− 107Ag
108Pd26.5%stable
110Pd11.7%stable
Standard atomic weight Ar°(Pd)

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 a half an hour except 101Pd (half-life: 8.47 hours), 109Pd (half-life: 13.7 hours), and 112Pd (half-life: 21 hours).

Contents

The primary decay mode before the most abundant stable isotope, 106Pd, is electron capture and the primary mode after is beta decay. The primary decay product before 106Pd is rhodium and the primary product after is silver.

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)
[n 2] [n 3] 		Half-life
[n 4] 		Decay
mode
[n 5] 		Daughter
isotope
[n 6] 		Spin and
parity
[n 7] [n 4] 		Natural abundance (mole fraction)
Excitation energy [n 4] Normal proportionRange of variation
91Pd464590.94911(61)#10# ms [>1.5 µs] β+ 91Rh7/2+#
92Pd464691.94042(54)#1.1(3) s [0.7(+4−2) s]β+92Rh0+
93Pd464792.93591(43)#1.07(12) sβ+93Rh(9/2+)
93mPd0+X keV9.3(+25−17) s
94Pd464893.92877(43)#9.0(5) sβ+94Rh0+
94mPd4884.4(5) keV530(10) ns(14+)
95Pd464994.92469(43)#10# sβ+95Rh9/2+#
95mPd1860(500)# keV13.3(3) sβ+ (94.1%)95Rh(21/2+)
IT (5%)95Pd
β+, p (.9%)94Ru
96Pd465095.91816(16)122(2) sβ+96Rh0+
96mPd2530.8(1) keV1.81(1) µs8+
97Pd465196.91648(32)3.10(9) minβ+97Rh5/2+#
98Pd465297.912721(23)17.7(3) minβ+98Rh0+
99Pd465398.911768(16)21.4(2) minβ+99Rh(5/2)+
100Pd465499.908506(12)3.63(9) d EC 100Rh0+
101Pd4655100.908289(19)8.47(6) hβ+101Rh5/2+
102Pd4656101.905609(3) Observationally Stable [n 8] 0+0.0102(1)
103Pd [n 9] 4657102.906087(3)16.991(19) dEC103Rh5/2+
103mPd784.79(10) keV25(2) ns11/2−
104Pd4658103.904036(4)Stable0+0.1114(8)
105Pd [n 10] 4659104.905085(4)Stable5/2+0.2233(8)
106Pd [n 10] 4660105.903486(4)Stable0+0.2733(3)
107Pd [n 11] 4661106.905133(4)6.5(3)×106 yβ−107Ag5/2+trace [n 12]
107m1Pd115.74(12) keV0.85(10) µs1/2+
107m2Pd214.6(3) keV21.3(5) sIT107Pd11/2−
108Pd [n 10] 4662107.903892(4)Stable0+0.2646(9)
109Pd [n 10] 4663108.905950(4)13.7012(24) hβ−109mAg5/2+
109m1Pd113.400(10) keV380(50) ns1/2+
109m2Pd188.990(10) keV4.696(3) minIT109Pd11/2−
110Pd [n 10] 4664109.905153(12)Observationally Stable [n 13] 0+0.1172(9)
111Pd4665110.907671(12)23.4(2) minβ−111mAg5/2+
111mPd172.18(8) keV5.5(1) hIT111Pd11/2−
β−111mAg
112Pd4666111.907314(19)21.03(5) hβ−112Ag0+
113Pd4667112.91015(4)93(5) sβ−113mAg(5/2+)
113mPd81.1(3) keV0.3(1) sIT113Pd(9/2−)
114Pd4668113.910363(25)2.42(6) minβ−114Ag0+
115Pd4669114.91368(7)25(2) sβ−115mAg(5/2+)#
115mPd89.18(25) keV50(3) sβ− (92%)115Ag(11/2−)#
IT (8%)115Pd
116Pd4670115.91416(6)11.8(4) sβ−116Ag0+
117Pd4671116.91784(6)4.3(3) sβ−117mAg(5/2+)
117mPd203.2(3) keV19.1(7) msIT117Pd(11/2−)#
118Pd4672117.91898(23)1.9(1) sβ−118Ag0+
119Pd4673118.92311(32)#0.92(13) sβ−119Ag
120Pd4674119.92469(13)0.5(1) sβ−120Ag0+
121Pd4675120.92887(54)#285 msβ−121Ag
122Pd4676121.93055(43)#175 ms [>300 ns]β−122Ag0+
123Pd4677122.93493(64)#108 msβ−123Ag
124Pd4678123.93688(54)#38 msβ−124Ag0+
125Pd [6] 467957 msβ−125Ag
126Pd [7] [8] 468048.6 msβ−126Ag0+
126m1Pd2023 keV330 nsIT126Pd5−
126m2Pd2110 keV440 nsIT126m1Pd7−
127Pd468138 msβ−127Ag
128Pd [7] [8] 468235 msβ−128Ag0+
128mPd2151 keV5.8 µsIT128Pd8+
129Pd468331 msβ−129Ag
This table header & footer:
  1. ↑ mPd – 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. 1 2 3 # – 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
    p: Proton emission
  6. ↑ Bold symbol as daughter – Daughter product is stable.
  7. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  8. ↑ Believed to decay by β+β+ to 102Ru
  9. ↑ Used in medicine
  10. 1 2 3 4 5 Fission product
  11. ↑ Long-lived fission product
  12. ↑ Cosmogenic nuclide, also found as nuclear contamination
  13. ↑ Believed to decay by β−β− to 110Cd with a half-life over 6×1017 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
Nuclide t1⁄2 Yield Q [a 1] βγ
(Ma)(%) [a 2] (keV)
99Tc 0.2116.1385294β
126Sn 0.2300.10844050 [a 3] βγ
79Se 0.3270.0447151β
135Cs 1.33 6.9110 [a 4] 269β
93Zr 1.53 5.457591βγ
107Pd 6.5  1.249933β
129I 15.7  0.8410194βγ
  1. ↑ Decay energy is split among β, neutrino, and γ if any.
  2. ↑ Per 65 thermal neutron fissions of 235U and 35 of 239Pu.
  3. ↑ Has decay energy 380 keV, but its decay product 126Sb has decay energy 3.67 MeV.
  4. ↑ 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 0.1629% per fission[ citation needed ], 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, 3.3%. Fast fission or fission of some heavier actinides [which?] will produce palladium-107 at higher yields.

One source [10] 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

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 gadolinium (64Gd) is composed of 6 stable isotopes, 154Gd, 155Gd, 156Gd, 157Gd, 158Gd and 160Gd, and 1 radioisotope, 152Gd, with 158Gd being the most abundant (24.84% natural abundance). The predicted double beta decay of 160Gd has never been observed; only a lower limit on its half-life of more than 1.3×1021 years has been set experimentally.

Naturally occurring europium (63Eu) is composed of two isotopes, 151Eu and 153Eu, with 153Eu being the most abundant (52.2% natural abundance). While 153Eu is observationally stable (theoretically can undergo alpha decay with half-life over 5.5×1017 years), 151Eu was found in 2007 to be unstable and undergo alpha decay. The half-life is measured to be (4.62 ± 0.95(stat.) ± 0.68(syst.)) × 1018 years which corresponds to 1 alpha decay per two minutes in every kilogram of natural europium. Besides the natural radioisotope 151Eu, 36 artificial radioisotopes have been characterized, with the most stable being 150Eu with a half-life of 36.9 years, 152Eu with a half-life of 13.516 years, 154Eu with a half-life of 8.593 years, and 155Eu with a half-life of 4.7612 years. The majority of the remaining radioactive isotopes, which range from 130Eu to 170Eu, have half-lives that are less than 12.2 seconds. This element also has 18 meta states, with the most stable being 150mEu (t1/2 12.8 hours), 152m1Eu (t1/2 9.3116 hours) and 152m2Eu (t1/2 96 minutes).

Naturally occurring samarium (62Sm) is composed of five stable isotopes, 144Sm, 149Sm, 150Sm, 152Sm and 154Sm, and two extremely long-lived radioisotopes, 147Sm (half life: 1.06×1011 y) and 148Sm (6.3×1015 y), with 152Sm being the most abundant (26.75% natural abundance). 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. A 2012 paper revising the estimated half-life of 146Sm from 10.3(5)×107 y to 6.8(7)×107 y was retracted in 2023. It is the longest-lived nuclide that has not yet been confirmed to be primordial.

Promethium (61Pm) is an artificial element, except in trace quantities as a product of spontaneous fission of 238U and 235U and alpha decay of 151Eu, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was first synthesized in 1945.

Caesium (55Cs) has 41 known isotopes, the atomic masses of these isotopes range from 112 to 152. Only one isotope, 133Cs, is stable. The longest-lived radioisotopes are 135Cs with a half-life of 1.33 million years, 137
Cs
 with a half-life of 30.1671 years and 134Cs with a half-life of 2.0652 years. All other isotopes have half-lives less than 2 weeks, most under an hour.

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. Moreover, tin is not only the element with the greatest number of observationally stable isotopes, but also the element with the greatest number of theoretically 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.

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 (t1/2 14.1 years), 115mCd (t1/2 44.6 days) and 117mCd (t1/2 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.

Technetium (43Tc) is one of the two elements with Z < 83 that have no stable isotopes; the other such element is promethium. It is primarily artificial, with only trace quantities existing in nature produced by spontaneous fission or neutron capture by molybdenum. The first isotopes to be synthesized were 97Tc and 99Tc in 1936, the first artificial element to be produced. The most stable radioisotopes are 97Tc, 98Tc, and 99Tc.

Molybdenum (42Mo) has 33 known isotopes, ranging in atomic mass from 83 to 115, 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 niobium (41Nb) is composed of one stable isotope (93Nb). The most stable radioisotope is 92Nb with a half-life of 34.7 million years. The next longest-lived niobium isotopes are 94Nb and 91Nb with a half-life of 680 years. There is also a meta state of 93Nb at 31 keV whose half-life is 16.13 years. Twenty-seven other radioisotopes have been characterized. Most of these have half-lives that are less than two hours, except 95Nb, 96Nb and 90Nb. The primary decay mode before stable 93Nb is electron capture and the primary mode after is beta emission with some neutron emission occurring in 104–110Nb.

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 t1/2 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.

Natural yttrium (39Y) is composed of a single isotope yttrium-89. The most stable radioisotopes are 88Y, which has a half-life of 106.6 days and 91Y with a half-life of 58.51 days. All the other isotopes have half-lives of less than a day, except 87Y, which has a half-life of 79.8 hours, and 90Y, with 64 hours. The dominant decay mode below the stable 89Y is electron capture and the dominant mode after it is beta emission. Thirty-five unstable isotopes have been characterized.

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).

There are 34 known isotopes of krypton (36Kr) with atomic mass numbers from 69 through 102. Naturally occurring krypton is made of five stable isotopes and one which is slightly radioactive with an extremely long half-life, plus traces of radioisotopes that are produced by cosmic rays in the atmosphere.

Germanium (32Ge) has five naturally occurring isotopes, 70Ge, 72Ge, 73Ge, 74Ge, and 76Ge. Of these, 76Ge is very slightly radioactive, decaying by double beta decay with a half-life of 1.78 × 1021 years (130 billion times the age of the universe).

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 238Pu 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. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight meta states; all have half-lives of less than one second.

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: Palladium". CIAAW. 1979.
  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.
  6. ↑ Future Plan of the Experimental Program on Synthesizing the Heaviest Element at RIKEN, Kosuke Morita Archived September 17, 2012, at the Wayback Machine
  7. 1 2 H. Watanabe; et al. (2013-10-08). "Isomers in 128Pd and 126Pd: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes" (PDF). Physical Review Letters. 111 (15): 152501. Bibcode:2013PhRvL.111o2501W. doi:10.1103/PhysRevLett.111.152501. hdl: 2437/215438 . PMID   24160593.
  8. 1 2 "Experiments on neutron-rich atomic nuclei could help scientists to understand nuclear reactions in exploding stars". phys.org. 2013-11-29.
  9. 1 2 Winter, Mark. "Isotopes of palladium". WebElements. The University of Sheffield and WebElements Ltd, UK. Retrieved 4 March 2013.
  10. ↑ R. P. Bush (1991). "Recovery of Platinum Group Metals from High Level Radioactive Waste" (PDF). Platinum Metals Review. 35 (4): 202–208. Archived from the original (PDF) on 2015-09-24. Retrieved 2011-04-02.
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.