Editing Palladium (section)

===Isotopes===
{{Main|Isotopes of palladium}}
Naturally occurring palladium is composed of seven [[isotope]]s, six of which are stable. The most stable [[radioisotope]]s are [[Palladium-107|<sup>107</sup>Pd]] with a [[half-life]] of 6.5 million years (found in nature), [[Pd-103|<sup>103</sup>Pd]] with 17 days, and <sup>100</sup>Pd with 3.63 days. Eighteen other radioisotopes have been characterized with [[atomic weight]]s ranging from 90.94948(64) [[atomic mass unit|u]] (<sup>91</sup>Pd) to 122.93426(64)&nbsp;u (<sup>123</sup>Pd).<ref>{{cite journal |access-date=12 November 2009 |url=http://physics.nist.gov/PhysRefData/Compositions/index.html |title=Atomic Weights and Isotopic Compositions for Palladium (NIST) |journal=NIST |date=2009-08-23}}</ref> These have half-lives of less than thirty minutes, except <sup>101</sup>Pd (half-life: 8.47 hours), <sup>109</sup>Pd (half-life: 13.7 hours), and <sup>112</sup>Pd (half-life: 21 hours).<ref name="NUBASE">{{NUBASE 2003}}</ref>

For isotopes with atomic mass unit values less than that of the most abundant stable isotope, <sup>106</sup>Pd, the primary [[decay mode]] is [[electron capture]] with the primary [[decay product]] being rhodium. The primary mode of decay for those isotopes of Pd with atomic mass greater than 106 is [[beta decay]] with the primary product of this decay being [[silver]].<ref name="NUBASE" />

[[Radiogenic]] <sup>107</sup>Ag is a decay product of <sup>107</sup>Pd and was first discovered in 1978<ref>{{cite journal |title=Evidence for the existence of <sup>107</sup>Pd in the early solar system |journal=Philosophical Transactions of the Royal Society of London, Series A |first3=R. |date=1978 |volume=359 |last3=Hutchison |pages=1079–1082 |doi=10.1098/rsta.2001.0893 |first1=W. R. |last1=Kelly |first2=G. J. |last2=Gounelle |issue=1787 |bibcode=2001RSPTA.359.1991R |s2cid=120355895}}</ref> in the [[Santa Clara, Durango|Santa Clara]]<ref>{{cite web |url=http://mexicogemstones.com/pdf/MexicoMeteorites.pdf |archive-url=https://web.archive.org/web/20060506085632/http://www.mexicogemstones.com/pdf/MexicoMeteorites.pdf |url-status=dead |archive-date=2006-05-06 |title=Mexico's Meteorites |work=mexicogemstones.com}}</ref> meteorite of 1976. The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a [[nucleosynthetic]] event. <sup>107</sup>Pd versus Ag correlations observed in bodies, which have been melted since accretion of the [[Solar System]], must reflect the presence of short-lived nuclides in the early Solar System.<ref>{{cite journal |title=The isotopic composition of Ag in meteorites and the presence of <sup>107</sup>Pd in protoplanets |journal=Geochimica et Cosmochimica Acta |date=1990 |volume=54 |issue=6 |pages=1729–1743 |doi=10.1016/0016-7037(90)90404-9 |first1=J. H. |last1=Chen |first2=G. J. |last2=Wasserburg |bibcode=1990GeCoA..54.1729C}}</ref> {{chem|107|Pd}} is also produced as a [[fission product]] in spontaneous or induced fission of {{chem|235|U|link=Uranium-235}}. As it is not very mobile in the environment and has a relatively low [[decay energy]], {{chem|107|Pd}} is usually considered to be among the less concerning of the [[long-lived fission products]].