Editing Silver (section)

===Isotopes===
{{Main|Isotopes of silver}}

Naturally occurring silver is composed of two stable [[isotope]]s, <sup>107</sup>Ag and <sup>109</sup>Ag, with <sup>107</sup>Ag being slightly more abundant (51.839% [[natural abundance]]). This almost equal abundance is rare in the periodic table. The [[atomic weight]] is 107.8682(2) [[atomic mass unit|u]];<ref name="Atomic Weights of the Elements 2007">{{cite web|access-date = 11 November 2009|url = http://www.chem.qmul.ac.uk/iupac/AtWt/index.html|title = Atomic Weights of the Elements 2007 (IUPAC)|archive-url = https://web.archive.org/web/20170906114640/http://www.chem.qmul.ac.uk/iupac/AtWt/index.html|archive-date = 6 September 2017|url-status = dead}}</ref><ref>{{cite web|access-date = 11 November 2009|url = http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=&ascii=html&isotype=some|title = Atomic Weights and Isotopic Compositions for All Elements (NIST)}}</ref> this value is very important because of the importance of silver compounds, particularly halides, in [[gravimetric analysis]].<ref name="Atomic Weights of the Elements 2007" /> Both isotopes of silver are produced in stars via the [[s-process]] (slow neutron capture), as well as in supernovas via the [[r-process]] (rapid neutron capture).<ref name="Cameron-1973">{{cite journal | last1 = Cameron |first1 = A.G.W. | year = 1973 | title = Abundance of the Elements in the Solar System | url = https://pubs.giss.nasa.gov/docs/1973/1973_Cameron_ca06310p.pdf | journal = Space Science Reviews | volume = 15 |issue = 1 | pages = 121–46 | doi = 10.1007/BF00172440 | bibcode = 1973SSRv...15..121C |s2cid = 120201972 }}</ref>

Twenty-eight [[radioisotope]]s have been characterised, the most stable being <sup>105</sup>Ag with a [[half-life]] of 41.29 days, <sup>111</sup>Ag with a half-life of 7.45 days, and <sup>112</sup>Ag with a half-life of 3.13 hours. Silver has numerous [[nuclear isomer]]s, the most stable being <sup>108m</sup>Ag (''t''<sub>1/2</sub> = 418 years), <sup>110m</sup>Ag (''t''<sub>1/2</sub> = 249.79 days) and <sup>106m</sup>Ag (''t''<sub>1/2</sub> = 8.28 days). All of the remaining [[radioactive]] isotopes have half-lives of less than an hour, and the majority of these have half-lives of less than three minutes.<ref name="Audi-2003">{{NUBASE 2003}}</ref>

Isotopes of silver range in [[Atomic weight|relative atomic mass]] from 92.950&nbsp;u (<sup>93</sup>Ag) to 129.950&nbsp;u (<sup>130</sup>Ag);<ref>{{cite web|access-date = 11 November 2009|url = http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=Ag&ascii=html&isotype=all|title = Atomic Weights and Isotopic Compositions for Silver (NIST)}}</ref> the primary [[decay mode]] before the most abundant stable isotope, <sup>107</sup>Ag, is [[electron capture]] and the primary mode after is [[beta decay]]. The primary [[decay product]]s before <sup>107</sup>Ag are [[palladium]] (element 46) isotopes, and the primary products after are [[cadmium]] (element 48) isotopes.<ref name="Audi-2003" />

The palladium [[isotope]] <sup>107</sup>Pd decays by beta emission to <sup>107</sup>Ag with a half-life of 6.5 million years. [[Iron meteorite]]s are the only objects with a high-enough palladium-to-silver ratio to yield measurable variations in <sup>107</sup>Ag abundance. [[Radiogenic]] <sup>107</sup>Ag was first discovered in the [[Santa Clara, Durango|Santa Clara]] meteorite in 1978.<ref>{{cite journal|doi = 10.1029/GL005i012p01079|title = Evidence for the existence of <sup>107</sup>Pd in the early solar system|date = 1978|last1 = Kelly |first1=William R. |journal = Geophysical Research Letters|volume = 5|pages = 1079–82|first2 = G. J.|last2 = Wasserburg|bibcode=1978GeoRL...5.1079K|issue = 12|url = http://authors.library.caltech.edu/43037/1/grl921.pdf}}</ref> <sup>107</sup>Pd–<sup>107</sup>Ag correlations observed in bodies that have clearly been melted since the [[accretion (astrophysics)|accretion]] of the [[Solar System]] must reflect the presence of unstable nuclides in the early Solar System.<ref>{{cite journal|title = Origin of Short-Lived Radionuclides|first1 = Sara S.|last1 = Russell|author1-link = Sara Russell|last2=Gounelle|first2=Matthieu|last3=Hutchison|first3=Robert|journal = [[Philosophical Transactions of the Royal Society A]]|volume = 359|issue = 1787|date = 2001 |pages = 1991–2004|doi = 10.1098/rsta.2001.0893|jstor=3066270|bibcode = 2001RSPTA.359.1991R |s2cid = 120355895}}</ref>