Isotopes of palladium
Naturally occurring palladium (Pd) is composed of six stable isotopes, 102Pd, 104Pd, 105Pd, 106Pd, 108Pd, and 110Pd, although two of them 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 123.937 u (124Pd). 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).
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, California meteorite of 1978.[1] 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.[2]
Standard atomic mass: 106.42(1) u
Palladium-103
Palladium-103 is a radioisotope of the element palladium which 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[3] days and decays by electron capture to rhodium-103, emitting gamma-rays with 21 keV of energy.
Palladium-107
Nuclide | t1⁄2 | 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 | 16.14 | 0.8410 | 194 | βγ |
Palladium-107 is the second longest lived (halflife of 6.5 million years[3]) 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 (no gamma radiation) to Ag-107.
Its yield from thermal neutron fission of uranium-235 is 0.1629% per fission, only 1/4 that of iodine-129, and only 1/40 those of Tc-99, Zr-93, and Cs-135. Yield from U-233 is slightly lower, but yield from Pu-239 is much higher, 3.3%. Yields are higher in fast fission or in fission of heavier nuclei.
According to [4] fission palladium 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 U-235, 11.8% for U-233, and 20.4% for Pu-239. (and the Pu-239 yield of palladium is about 10 times that of U-235.)
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.
Table
nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life | decay mode(s)[5][n 1] |
daughter isotope(s)[n 2] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
---|---|---|---|---|---|---|---|---|---|
excitation energy | |||||||||
91Pd | 46 | 45 | 90.94911(61)# | 10# ms [>1.5 µs] | β+ | 91Rh | 7/2+# | ||
92Pd | 46 | 46 | 91.94042(54)# | 1.1(3) s [0.7(+4-2) s] | β+ | 92Rh | 0+ | ||
93Pd | 46 | 47 | 92.93591(43)# | 1.07(12) s | β+ | 93Rh | (9/2+) | ||
93mPd | 0+X keV | 9.3(+25-17) s | |||||||
94Pd | 46 | 48 | 93.92877(43)# | 9.0(5) s | β+ | 94Rh | 0+ | ||
94mPd | 4884.4(5) keV | 530(10) ns | (14+) | ||||||
95Pd | 46 | 49 | 94.92469(43)# | 10# s | β+ | 95Rh | 9/2+# | ||
95mPd | 1860(500)# keV | 13.3(3) s | β+ (94.1%) | 95Rh | (21/2+) | ||||
IT (5%) | 95Pd | ||||||||
β+, p (.9%) | 94Ru | ||||||||
96Pd | 46 | 50 | 95.91816(16) | 122(2) s | β+ | 96Rh | 0+ | ||
96mPd | 2530.8(1) keV | 1.81(1) µs | 8+ | ||||||
97Pd | 46 | 51 | 96.91648(32) | 3.10(9) min | β+ | 97Rh | 5/2+# | ||
98Pd | 46 | 52 | 97.912721(23) | 17.7(3) min | β+ | 98Rh | 0+ | ||
99Pd | 46 | 53 | 98.911768(16) | 21.4(2) min | β+ | 99Rh | (5/2)+ | ||
100Pd | 46 | 54 | 99.908506(12) | 3.63(9) d | EC | 100Rh | 0+ | ||
101Pd | 46 | 55 | 100.908289(19) | 8.47(6) h | β+ | 101Rh | 5/2+ | ||
102Pd | 46 | 56 | 101.905609(3) | Observationally Stable[n 3] | 0+ | 0.0102(1) | |||
103Pd[n 4] | 46 | 57 | 102.906087(3) | 16.991(19) d | EC | 103Rh | 5/2+ | ||
103mPd | 784.79(10) keV | 25(2) ns | 11/2- | ||||||
104Pd | 46 | 58 | 103.904036(4) | Stable[n 5] | 0+ | 0.1114(8) | |||
105Pd[n 6] | 46 | 59 | 104.905085(4) | Stable[n 5] | 5/2+ | 0.2233(8) | |||
106Pd[n 6] | 46 | 60 | 105.903486(4) | Stable[n 5] | 0+ | 0.2733(3) | |||
107Pd[n 7] | 46 | 61 | 106.905133(4) | 6.5(3)×106 a | β- | 107Ag | 5/2+ | ||
107m1Pd | 115.74(12) keV | 0.85(10) µs | 1/2+ | ||||||
107m2Pd | 214.6(3) keV | 21.3(5) s | IT | 107Pd | 11/2- | ||||
108Pd[n 6] | 46 | 62 | 107.903892(4) | Stable[n 5] | 0+ | 0.2646(9) | |||
109Pd[n 6] | 46 | 63 | 108.905950(4) | 13.7012(24) h | β- | 109mAg | 5/2+ | ||
109m1Pd | 113.400(10) keV | 380(50) ns | 1/2+ | ||||||
109m2Pd | 188.990(10) keV | 4.696(3) min | IT | 109Pd | 11/2- | ||||
110Pd[n 6] | 46 | 64 | 109.905153(12) | Observationally Stable[n 8] | 0+ | 0.1172(9) | |||
111Pd | 46 | 65 | 110.907671(12) | 23.4(2) min | β- | 111mAg | 5/2+ | ||
111mPd | 172.18(8) keV | 5.5(1) h | IT | 111Pd | 11/2- | ||||
β- | 111mAg | ||||||||
112Pd | 46 | 66 | 111.907314(19) | 21.03(5) h | β- | 112Ag | 0+ | ||
113Pd | 46 | 67 | 112.91015(4) | 93(5) s | β- | 113mAg | (5/2+) | ||
113mPd | 81.1(3) keV | 0.3(1) s | IT | 113Pd | (9/2-) | ||||
114Pd | 46 | 68 | 113.910363(25) | 2.42(6) min | β- | 114Ag | 0+ | ||
115Pd | 46 | 69 | 114.91368(7) | 25(2) s | β- | 115mAg | (5/2+)# | ||
115mPd | 89.18(25) keV | 50(3) s | β- (92%) | 115Ag | (11/2-)# | ||||
IT (8%) | 115Pd | ||||||||
116Pd | 46 | 70 | 115.91416(6) | 11.8(4) s | β- | 116Ag | 0+ | ||
117Pd | 46 | 71 | 116.91784(6) | 4.3(3) s | β- | 117mAg | (5/2+) | ||
117mPd | 203.2(3) keV | 19.1(7) ms | IT | 117Pd | (11/2-)# | ||||
118Pd | 46 | 72 | 117.91898(23) | 1.9(1) s | β- | 118Ag | 0+ | ||
119Pd | 46 | 73 | 118.92311(32)# | 0.92(13) s | β- | 119Ag | |||
120Pd | 46 | 74 | 119.92469(13) | 0.5(1) s | β- | 120Ag | 0+ | ||
121Pd | 46 | 75 | 120.92887(54)# | 400# ms [>300 ns] | β- | 121Ag | |||
122Pd | 46 | 76 | 121.93055(43)# | 300# ms [>300 ns] | β- | 122Ag | 0+ | ||
123Pd | 46 | 77 | 122.93493(64)# | 200# ms [>300 ns] | β- | 123Ag | |||
124Pd | 46 | 78 | 123.93688(54)# | 100# ms [>300 ns] | 0+ | ||||
125Pd[6] | 46 | 79 | |||||||
126Pd[7][8] | 46 | 80 | 0+ | ||||||
126m1Pd | 2023 keV | 330 ns | IT | 126Pd | 5- | ||||
126m2Pd | 2110 keV | 440 ns | IT | 126m1Pd | 7- | ||||
128Pd[7][8] | 46 | 82 | 0+ | ||||||
128mPd | 2151 keV | 5.8 µs | IT | 128Pd | 8+ |
- ^ Abbreviations:
EC: Electron capture
IT: Isomeric transition - ^ Bold for stable isotopes
- ^ Believed to decay by β+β+ to 102Ru
- ^ Used in medicine
- ^ a b c d Theoretically capable of spontaneous fission
- ^ a b c d e Fission product
- ^ Long-lived fission product
- ^ Believed to decay by β-β- to 110Cd with a half-life over 6×1017 years
Notes
- The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
- Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
- Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
- Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.
References
- Patent application for Palladium-103 implantable radiation-delivery device (accessed 12/7/05)
- ^ 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.
- ^ a b Winter, Mark. "Isotopes of palladium". WebElements. The University of Sheffield and WebElements Ltd, UK. Retrieved 4 March 2013.
- ^ http://www.platinummetalsreview.com/pdf/pmr-v35-i4-202-208.pdf
- ^ http://www.nucleonica.net/unc.aspx
- ^ Future Plan of the Experimental Program on Synthesizing the Heaviest Element at RIKEN, Kosuke Morita
- ^ a b Isomers in 128Pd and 126Pd: Evidence for a Robust Shell Closure at the Neutron Magic Number 82 in Exotic Palladium Isotopes; Physical Review Letters, 11/29/2013
- ^ a b Experiments on neutron-rich atomic nuclei could help scientists to understand nuclear reactions in exploding stars; physorg.com, 11/29/2013
- Isotope masses from:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
{{cite journal}}
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ignored (help)
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
{{cite web}}
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(help) - N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide (ed.). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.
{{cite book}}
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suggested) (help)
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.