Isotopes of palladium

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Isotopes of palladium   ( 46 Pd)
Main isotopes [1] Decay
abun­dance half-life ( t 1/2 ) mode pro­duct
100 Pd synth 3.63 d ε 100 Rh
γ ?
102 Pd 1.02% stable
103 Pd synth 16.991 d ε 103 Rh
104 Pd 11.1% stable
105 Pd 22.3% stable
106 Pd 27.3% stable
107 Pd trace 6.5 × 10 6  y β ? 107 Ag
108 Pd 26.5% stable
110 Pd 11.7% stable
Standard atomic weight A r °(Pd)

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

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

Radiogenic 107 Ag is a decay product of 107 Pd 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. 107 Pd 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 [ edit ]

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 proportion Range of variation
91 Pd 46 45 90.94911(61)# 10# ms [>1.5 μs] β + 91 Rh 7/2+#
92 Pd 46 46 91.94042(54)# 1.1(3) s [0.7(+4?2) s] β + 92 Rh 0+
93 Pd 46 47 92.93591(43)# 1.07(12) s β + 93 Rh (9/2+)
93m Pd 0+X keV 9.3(+25?17) s
94 Pd 46 48 93.92877(43)# 9.0(5) s β + 94 Rh 0+
94m Pd 4884.4(5) keV 530(10) ns (14+)
95 Pd 46 49 94.92469(43)# 10# s β + 95 Rh 9/2+#
95m Pd 1860(500)# keV 13.3(3) s β + (94.1%) 95 Rh (21/2+)
IT (5%) 95 Pd
β + , p (.9%) 94 Ru
96 Pd 46 50 95.91816(16) 122(2) s β + 96 Rh 0+
96m Pd 2530.8(1) keV 1.81(1) μs 8+
97 Pd 46 51 96.91648(32) 3.10(9) min β + 97 Rh 5/2+#
98 Pd 46 52 97.912721(23) 17.7(3) min β + 98 Rh 0+
99 Pd 46 53 98.911768(16) 21.4(2) min β + 99 Rh (5/2)+
100 Pd 46 54 99.908506(12) 3.63(9) d EC 100 Rh 0+
101 Pd 46 55 100.908289(19) 8.47(6) h β + 101 Rh 5/2+
102 Pd 46 56 101.905609(3) Observationally Stable [n 8] 0+ 0.0102(1)
103 Pd [n 9] 46 57 102.906087(3) 16.991(19) d EC 103 Rh 5/2+
103m Pd 784.79(10) keV 25(2) ns 11/2?
104 Pd 46 58 103.904036(4) Stable 0+ 0.1114(8)
105 Pd [n 10] 46 59 104.905085(4) Stable 5/2+ 0.2233(8)
106 Pd [n 10] 46 60 105.903486(4) Stable 0+ 0.2733(3)
107 Pd [n 11] 46 61 106.905133(4) 6.5(3)×10 6 y β ? 107 Ag 5/2+ trace [n 12]
107m1 Pd 115.74(12) keV 0.85(10) μs 1/2+
107m2 Pd 214.6(3) keV 21.3(5) s IT 107 Pd 11/2?
108 Pd [n 10] 46 62 107.903892(4) Stable 0+ 0.2646(9)
109 Pd [n 10] 46 63 108.905950(4) 13.7012(24) h β ? 109m Ag 5/2+
109m1 Pd 113.400(10) keV 380(50) ns 1/2+
109m2 Pd 188.990(10) keV 4.696(3) min IT 109 Pd 11/2?
110 Pd [n 10] 46 64 109.905153(12) Observationally Stable [n 13] 0+ 0.1172(9)
111 Pd 46 65 110.907671(12) 23.4(2) min β ? 111m Ag 5/2+
111m Pd 172.18(8) keV 5.5(1) h IT 111 Pd 11/2?
β ? 111m Ag
112 Pd 46 66 111.907314(19) 21.03(5) h β ? 112 Ag 0+
113 Pd 46 67 112.91015(4) 93(5) s β ? 113m Ag (5/2+)
113m Pd 81.1(3) keV 0.3(1) s IT 113 Pd (9/2?)
114 Pd 46 68 113.910363(25) 2.42(6) min β ? 114 Ag 0+
115 Pd 46 69 114.91368(7) 25(2) s β ? 115m Ag (5/2+)#
115m Pd 89.18(25) keV 50(3) s β ? (92%) 115 Ag (11/2?)#
IT (8%) 115 Pd
116 Pd 46 70 115.91416(6) 11.8(4) s β ? 116 Ag 0+
117 Pd 46 71 116.91784(6) 4.3(3) s β ? 117m Ag (5/2+)
117m Pd 203.2(3) keV 19.1(7) ms IT 117 Pd (11/2?)#
118 Pd 46 72 117.91898(23) 1.9(1) s β ? 118 Ag 0+
119 Pd 46 73 118.92311(32)# 0.92(13) s β ? 119 Ag
120 Pd 46 74 119.92469(13) 0.5(1) s β ? 120 Ag 0+
121 Pd 46 75 120.92887(54)# 285 ms β ? 121 Ag
122 Pd 46 76 121.93055(43)# 175 ms [>300 ns] β ? 122 Ag 0+
123 Pd 46 77 122.93493(64)# 108 ms β ? 123 Ag
124 Pd 46 78 123.93688(54)# 38 ms β ? 124 Ag 0+
125 Pd [6] 46 79 57 ms β ? 125 Ag
126 Pd [7] [8] 46 80 48.6 ms β ? 126 Ag 0+
126m1 Pd 2023 keV 330 ns IT 126 Pd 5?
126m2 Pd 2110 keV 440 ns IT 126m1 Pd 7?
127 Pd 46 81 38 ms β ? 127 Ag
128 Pd [7] [8] 46 82 35 ms β ? 128 Ag 0+
128m Pd 2151 keV 5.8 μs IT 128 Pd 8+
129 Pd 46 83 31 ms β ? 129 Ag
This table header & footer:
  1. ^ m Pd – Excited nuclear isomer .
  2. ^ ( ) – Uncertainty (1 σ ) 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. ^ a b c # – 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 102 Ru
  9. ^ Used in medicine
  10. ^ a b c d e Fission product
  11. ^ Long-lived fission product
  12. ^ Cosmogenic nuclide, also found as nuclear contamination
  13. ^ Believed to decay by β ? β ? to 110 Cd with a half-life over 6×10 17 years

Palladium-103 [ edit ]

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 [ edit ]

Long-lived fission products
Nuclide t 1 ⁄ 2 Yield Q [a 1] βγ
( Ma ) (%) [a 2] ( keV )
99 Tc 0.211 6.1385 294 β
126 Sn 0.230 0.1084 4050 [a 3] β γ
79 Se 0.327 0.0447 151 β
135 Cs 1.33   6.9110 [a 4] 269 β
93 Zr 1.53   5.4575 91 βγ
107 Pd 6.5    1.2499 33 β
129 I 15.7    0.8410 194 βγ
  1. ^ Decay energy is split among β , neutrino , and γ if any.
  2. ^ Per 65 thermal neutron fissions of 235 U and 35 of 239 Pu .
  3. ^ Has decay energy 380 keV, but its decay product 126 Sb has decay energy 3.67 MeV.
  4. ^ Lower in thermal reactors because 135 Xe , 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 107 Ag , 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 99 Tc , 93 Zr , and 135 Cs . Yield from 233 U is slightly lower, but yield from 239 Pu 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 104 Pd (16.9%), 105 Pd (29.3%), 106 Pd (21.3%), 107 Pd (17%), 108 Pd (11.7%) and 110 Pd (3.8%). According to another source, the proportion of 107 Pd is 9.2% for palladium from thermal neutron fission of 235 U , 11.8% for 233 U, and 20.4% for 239 Pu (and the 239 Pu yield of palladium is about 10 times that of 235 U).

Because of this dilution and because 105 Pd has 11 times the neutron absorption cross section , 107 Pd 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.

References [ edit ]

  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; Bohlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Groning, 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 107 Pd 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 107 Pd 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. ^ a b H. Watanabe; et al. (2013-10-08). "Isomers in 128 Pd and 126 Pd: 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. ^ a b "Experiments on neutron-rich atomic nuclei could help scientists to understand nuclear reactions in exploding stars" . phys.org. 2013-11-29.
  9. ^ a b 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 .
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