Gold Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! === Isotopes === {{Main|Isotopes of gold}} Gold has only one stable [[isotope]], {{chem|197|Au}}, which is also its only naturally occurring isotope, so gold is both a [[Mononuclidic element|mononuclidic]] and [[monoisotopic element]]. Thirty-six [[radioisotopes]] have been synthesized, ranging in [[atomic mass]] from 169 to 205. The most stable of these is {{chem|195|Au}} with a [[half-life]] of 186.1 days. The least stable is {{chem|171|Au}}, which decays by [[proton emission]] with a half-life of 30 Β΅s. Most of gold's radioisotopes with atomic masses below 197 decay by some combination of [[proton emission]], [[alpha decay|Ξ± decay]], and [[Ξ²+ decay|Ξ²<sup>+</sup> decay]]. The exceptions are {{chem|195|Au}}, which decays by electron capture, and {{chem|196|Au}}, which decays most often by electron capture (93%) with a minor [[Ξ²β decay|Ξ²<sup>β</sup> decay]] path (7%).<ref>{{cite web |url=http://www.nndc.bnl.gov/nudat2/ |website=National Nuclear Data Center |title=Nudat 2 |access-date=12 April 2012}}</ref> All of gold's radioisotopes with atomic masses above 197 decay by Ξ²<sup>β</sup> decay.<ref name="nubase">{{NUBASE 2003}}</ref> At least 32 [[nuclear isomer]]s have also been characterized, ranging in atomic mass from 170 to 200. Within that range, only {{chem|178|Au}}, {{chem|180|Au}}, {{chem|181|Au}}, {{chem|182|Au}}, and {{chem|188|Au}} do not have isomers. Gold's most stable isomer is {{chem|198m2|Au}} with a half-life of 2.27 days. Gold's least stable isomer is {{chem|177m2|Au}} with a half-life of only 7 ns. {{chem|184m1|Au}} has three decay paths: Ξ²<sup>+</sup> decay, [[isomeric transition]], and alpha decay. No other isomer or isotope of gold has three decay paths.<ref name="nubase" /> ==== Synthesis ==== {{see also|Synthesis of precious metals}} The possible production of gold from a more common element, such as [[lead]], has long been a subject of human inquiry, and the ancient and medieval discipline of [[alchemy]] often focused on it; however, the transmutation of the chemical elements did not become possible until the understanding of [[nuclear physics]] in the 20th century. The first synthesis of gold was conducted by Japanese physicist [[Hantaro Nagaoka]], who synthesized gold from [[mercury (element)|mercury]] in 1924 by neutron bombardment.<ref>{{Cite journal |last1=Miethe |first1=A. |title=Der Zerfall des Quecksilberatoms |doi=10.1007/BF01505547 |journal=Die Naturwissenschaften |volume=12 |issue=29 |pages=597β598 |year=1924 |bibcode=1924NW.....12..597M|s2cid=35613814 }}</ref> An American team, working without knowledge of Nagaoka's prior study, conducted the same experiment in 1941, achieving the same result and showing that the [[isotopes of gold]] produced by it were all [[radioactive]].<ref>{{cite journal |last1=Sherr |first1=R. |first2=K. T. |last2=Bainbridge |first3=H. H. |last3=Anderson |name-list-style=amp |title=Transmutation of Mercury by Fast Neutrons |date=1941 |journal=[[Physical Review]] |volume=60 |issue=7 |pages=473β479 |doi=10.1103/PhysRev.60.473 |bibcode=1941PhRv...60..473S}}</ref> In 1980, [[Glenn T. Seaborg|Glenn Seaborg]] transmuted several thousand atoms of bismuth into gold at the Lawrence Berkeley Laboratory.<ref>{{Cite journal|last1=Aleklett |first1=K.|last2=Morrissey |first2=D.|last3=Loveland |first3=W.|last4=McGaughey |first4=P.|last5=Seaborg |first5=G.|year=1981|title=Energy dependence of <sup>209</sup>Bi fragmentation in relativistic nuclear collisions|journal=[[Physical Review C]]|volume=23 |issue=3 |page=1044|bibcode=1981PhRvC..23.1044A|doi=10.1103/PhysRevC.23.1044}}</ref><ref>{{cite news |url=https://www.telegraph.co.uk/education/4791069/The-Philosophers-Stone.html |newspaper=[[The Daily Telegraph]] |first=Robert |last=Matthews |title=The Philosopher's Stone |date=2 December 2001 |access-date=22 September 2020 }}</ref> Gold can be manufactured in a nuclear reactor, but doing so is highly impractical and would cost far more than the value of the gold that is produced.<ref>{{cite book |last1=Shipman |first1=James |last2=Wilson |first2=Jerry D. |last3=Higgins |first3=Charles A. |title=An Introduction to Physical Science |date=2012 |publisher=Cengage Learning |isbn=9781133709497 |page=273 |edition=13th}}</ref> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page