View source for Transuranium element

{{distinguish|Transactinide element}}
{{short description|Element whose atomic number is greater than 92}}
{{periodic table (micro)|title=Transuranium elements<br/>in the [[periodic table]]|caption=''Z''&nbsp;>&nbsp;92 (U)|mark=Np,Pu,Am,Cm,Bk,Cf,Es,Fm,Md,No,Lr,Rf,Db,Sg,Bh,Hs,Mt,Ds,Rg,Cn,Nh,Fl,Mc,Lv,Ts,Og}}
The '''transuranium''' (or '''transuranic''') '''elements''' are the [[chemical element]]s with [[atomic number]] greater than 92, which is the atomic number of [[uranium]]. All of them are [[Radioactive decay|radioactively unstable]] and decay into other elements. They are [[Synthetic element|synthetic]] and none occur naturally on Earth, except for [[neptunium]] and [[plutonium]] which have been found in trace amounts in nature.

==Overview==
{{Periodic table (transuranium element)}}

Of the elements with atomic numbers 1 to 92, most can be found in nature, having stable [[isotope]]s (such as [[lead]]) or very long-lived [[radioisotope]]s (such as [[uranium]]), or existing as common [[decay product]]s of the decay of uranium and [[thorium]] (such as [[radium]]). The exceptions are [[technetium]], [[promethium]], [[astatine]], and [[francium]]; all four occur in nature, but only in very minor branches of the uranium and thorium decay chains, and thus all except francium were first discovered by synthesis in the laboratory rather than in nature.

All elements with higher atomic numbers have been first discovered in the laboratory, with [[neptunium]] and [[plutonium]] (the first two of these) later discovered in nature. They are all [[radioactive]], with a [[half-life]] much shorter than the [[age of the Earth]], so any primordial (i.e. present at the Earth's formation) atoms of these elements, have long since decayed. Trace amounts of neptunium and plutonium form in some uranium-rich rock, and small amounts are produced during atmospheric tests of [[nuclear weapon]]s. These two elements are generated by [[neutron capture]] in [[uranium ore]] with subsequent [[beta decay]]s (e.g. [[Uranium-238|{{sup|238}}U]] + [[Neutron|n]] → [[Uranium-239|{{sup|239}}U]] → [[Neptunium-239|{{sup|239}}Np]] → [[Plutonium-239|{{sup|239}}Pu]]).

All elements beyond plutonium are entirely [[synthetic element|synthetic]], at least on Earth;<ref>{{cite journal | title=Origin of the heaviest elements: The rapid neutron-capture process | display-authors=1 | last1=Cowan | first1=John J. | last2=Sneden | first2=Christopher | last3=Lawler | first3=James E. | last4=Aprahamian | first4=Ani | last5=Wiescher | first5=Michael | last6=Langanke | first6=Karlheinz | last7=Martínez-Pinedo | first7=Gabriel | last8=Thielemann | first8=Friedrich-Karl | journal=Reviews of Modern Physics | volume=93 | issue=1 | article-number=015002 | date=January 2021 | doi=10.1103/RevModPhys.93.015002 | arxiv=1901.01410 | bibcode=2021RvMP...93a5002C }}</ref><ref>{{cite conference | title=On the radioactive shells in peculiar main sequence stars: the phenomenon of Przybylski's star | display-authors=1 | display-editors=1 | last1=Gopka | first1=Vera F. | last2=Yushchenko | first2=Alexander V. | last3=Shavrina | first3=Angelina V. | last4=Mkrtichian | first4=David E. | last5=Hatzes | first5=Artie P. | last6=Andrievsky | first6=Sergey M. | last7=Chernysheva | first7=Larissa V. | conference=The A-Star Puzzle, held in Poprad, Slovakia, July 8-13, 2004. IAU Symposium, No. 224 | editor1-first=J. | editor1-last=Zverko | editor2-first=J. | editor2-last=Ziznovsky | editor3-first=S. J. | editor3-last=Adelman | editor4-first=W. W. | editor4-last=Weiss | location=Cambridge, UK | publisher=Cambridge University Press | pages=734–742 | date=December 2004 | doi=10.1017/S174392130500966X | bibcode=2004IAUS..224..734G }}</ref> they are created in [[nuclear reactor]]s or [[particle accelerator]]s. The half-lives of these elements show a general trend of decreasing as atomic numbers increase. There are exceptions, however, including several isotopes of [[curium]] and [[dubnium]]. Some heavier elements in this series, around atomic numbers 110–114, are thought to break the trend and demonstrate increased nuclear stability, comprising the theoretical [[island of stability]].<ref>{{cite book |editor-first=Glenn |editor-last=Considine |title=Van Nostrand's Scientific Encyclopedia |edition=9th |location=New York |publisher=Wiley Interscience |year=2002 |page=738 |isbn=978-0-471-33230-5 }}</ref>

Transuranic elements are difficult and expensive to produce, and their prices increase rapidly with atomic number. As of 2008, the cost of weapons-grade plutonium was around $4,000/gram,<ref>{{cite web|url=https://hypertextbook.com/facts/2008/AndrewMorel.shtml|title=Price of Plutonium|last=Morel|first=Andrew|date=2008|editor-last=Elert|editor-first=Glenn|publisher=The Physics Factbook|archive-url=https://web.archive.org/web/20181020094114/https://hypertextbook.com/facts/2008/AndrewMorel.shtml|archive-date=20 October 2018|url-status=live}}</ref> and [[californium]] exceeded $60,000,000/gram.<ref>{{cite report|citeseerx=10.1.1.499.1273|title=Applications and Availability of Californium-252 Neutron Sources for Waste Characterization|last1=Martin|first1=Rodger C.|last2=Kos|first2=Steve E.|date=2001|url=https://archive.org/details/ApplicationsAndAvailabilityOfCalifornium252NeutronSourcesForWasteCharacterization}}</ref> [[Einsteinium]] is the heaviest element that has been produced in macroscopic quantities.<ref>{{cite book|title=The Chemistry of the Actinide and Transactinide Elements|last=Silva|first=Robert J.|publisher=[[Springer Science+Business Media]]|year=2006|isbn=978-1-4020-3555-5|editor1-last=Morss|editor-first=Lester R.|edition=Third|location=Dordrecht, The Netherlands|chapter=Fermium, Mendelevium, Nobelium and Lawrencium|ref=CITEREFHaire2006|editor2-last=Edelstein|editor2-first=Norman M.|editor3-last=Fuger|editor3-first=Jean}}</ref>

Transuranic elements that have not been discovered, or have been discovered but are not yet officially named, use [[International Union of Pure and Applied Chemistry|IUPAC]]'s [[systematic element name]]s. The naming of transuranic elements may be a source of [[Transfermium Wars|controversy]].

==Discoveries==
{{See also|Timeline of chemical element discoveries}}

So far, essentially all transuranium elements have been discovered at four laboratories: [[Lawrence Berkeley National Laboratory]] (LBNL) in the United States (elements 93–101, 106, and joint credit for 103–105), the [[GSI Helmholtz Centre for Heavy Ion Research]] in Germany (elements 107–112), [[RIKEN]] in Japan (element 113), and the [[Joint Institute for Nuclear Research]] (JINR) in Russia (elements 102 and 114–118, and joint credit for 103–105).
*The Radiation Laboratory (now LBNL) at [[University of California, Berkeley]], led principally by [[Edwin McMillan]], [[Glenn Seaborg]], and [[Albert Ghiorso]], during 1945–1974:
**93. [[neptunium]], Np, named after the planet [[Neptune]], as it follows [[uranium]] and Neptune follows [[Uranus]] in the [[giant planet|planetary sequence]] (1940).
**94. [[plutonium]], Pu, named after [[Pluto]],{{efn|Pluto was a planet at the time of naming, but has since been reclassified as a [[dwarf planet]].}} following the same naming rule as it follows neptunium and Pluto follows Neptune in the Solar System (1940).
**95. [[americium]], Am, named because it is an analog to [[europium]], and so was named after the continent where it was first produced (1944).
**96. [[curium]], Cm, named after [[Pierre Curie|Pierre]] and [[Marie Curie]], scientists who separated out the first radioactive elements (1944), as its lighter analog [[gadolinium]] was named after [[Johan Gadolin]].
**97. [[berkelium]], Bk, named after [[Lawrence Berkeley National Laboratory]], where it was first synthesized (1949).
**98. [[californium]], Cf, named after [[California]], where LBNL is located (1950).
**99. [[einsteinium]], Es, named after [[Albert Einstein]] (1952).
**100. [[fermium]], Fm, named after [[Enrico Fermi]], the physicist who produced the first controlled [[chain reaction]] (1952).
**101. [[mendelevium]], Md, named after Russian chemist [[Dmitri Mendeleev]], credited for being the primary creator of the [[periodic table]] of the [[chemical element]]s (1955).
**102. [[nobelium]], No, named after [[Alfred Nobel]] (1958). The element was originally claimed by a team at the [[Nobel Institute]] in Sweden (1957) – though it later became apparent that the Swedish team had not discovered the element, the LBNL team decided to adopt their name ''nobelium''. This discovery was also claimed by JINR, which doubted the LBNL claim, and named the element ''joliotium'' (Jl) after [[Frédéric Joliot-Curie]] (1965). IUPAC concluded that the JINR had been the first to convincingly synthesize the element (1965), but retained the name ''nobelium'' as deeply entrenched in the literature.
**103. [[lawrencium]], Lr, named after [[Ernest Lawrence]], a physicist best known for development of the [[cyclotron]], and the person for whom [[Lawrence Livermore National Laboratory]] and LBNL (which hosted the creation of these transuranium elements) are named (1961). This discovery was also claimed by the JINR (1965), which doubted the LBNL claim and proposed the name ''rutherfordium'' (Rf) after [[Ernest Rutherford]]. IUPAC concluded that credit should be shared, retaining the name ''lawrencium'' as entrenched in the literature.
**104. [[rutherfordium]], Rf, named after [[Ernest Rutherford]], who was responsible for the concept of the [[atomic nucleus]] (1969). This discovery was also claimed by JINR, led principally by [[Georgy Flyorov]]: they named the element ''kurchatovium'' (Ku), after [[Igor Kurchatov]]. IUPAC concluded that credit should be shared, and adopted the LBNL name ''rutherfordium''.
**105. [[dubnium]], Db, an element that is named after [[Dubna]], where JINR is located. Originally named ''hahnium'' (Ha) in honor of [[Otto Hahn]] by the Berkeley group (1970). This discovery was also claimed by JINR, which named it ''nielsbohrium'' (Ns) after [[Niels Bohr]]. IUPAC concluded that credit should be shared, and renamed the element ''dubnium'' to honour the JINR team.
**106. [[seaborgium]], Sg, named after [[Glenn T. Seaborg]]. This name caused controversy because Seaborg was still alive, but it eventually became accepted by international chemists (1974). This discovery was also claimed by JINR. IUPAC concluded that the Berkeley team had been the first to convincingly synthesize the element.
*The Gesellschaft für Schwerionenforschung (Society for Heavy Ion Research) in [[Darmstadt]], Hessen, Germany, led principally by [[Gottfried Münzenberg]], [[Peter Armbruster]], and [[Sigurd Hofmann]], during 1980–2000:
**107. [[bohrium]], Bh, named after Danish physicist [[Niels Bohr]], important in the elucidation of the structure of the [[atom]] (1981). This discovery was also claimed by JINR. IUPAC concluded that the GSI had been the first to convincingly synthesise the element. The GSI team had originally proposed ''nielsbohrium'' (Ns) to resolve the naming dispute on element 105, but this was changed by IUPAC as there was no precedent for using a scientist's first name in an element name.
**108. [[hassium]], Hs, named after the [[Latin]] form of the name of [[Hessen]], the German ''[[States of Germany|Bundesland]]'' where this work was performed (1984). This discovery was also claimed by JINR. IUPAC concluded that the GSI had been the first to convincingly synthesize the element, while acknowledging the pioneering work at JINR.
**109. [[meitnerium]], Mt, named after [[Lise Meitner]], an Austrian physicist who was one of the earliest scientists to study [[nuclear fission]] (1982).
**110. [[darmstadtium]], Ds, named after [[Darmstadt]], Germany, the city in which this work was performed (1994). This discovery was also claimed by JINR, which proposed the name ''becquerelium'' after [[Henri Becquerel]], and by LBNL, which proposed the name ''hahnium'' to resolve the dispute on element 105 (despite having protested the reusing of established names for different elements). IUPAC concluded that GSI had been the first to convincingly synthesize the element.
**111. [[roentgenium]], Rg, named after [[Wilhelm Röntgen]], discoverer of X-rays (1994).
**112. [[copernicium]], Cn, named after astronomer [[Nicolaus Copernicus]] (1996).
*RIKEN in [[Wakō, Saitama]], Japan, led principally by [[Kōsuke Morita]]:
**113. [[nihonium]], Nh, named after [[Japan]] (''Nihon'' in [[Japanese language|Japanese]]) where the element was discovered (2004). This discovery was also claimed by JINR. IUPAC concluded that RIKEN had been the first to convincingly synthesize the element.
*JINR in Dubna, Russia, led principally by [[Yuri Oganessian]], in collaboration with several other labs including [[Lawrence Livermore National Laboratory]] (LLNL), since 2000:
**114. [[flerovium]], Fl, named after the Flerov Laboratory of Nuclear Reactions in JINR (1999).
**115. [[moscovium]], Mc, named after [[Moscow Oblast]], where the element was discovered (2004).
**116. [[livermorium]], Lv, named after Lawrence Livermore National Laboratory, a collaborator with JINR in the discovery (2000).
**117. [[tennessine]], Ts, after [[Tennessee]], the location of [[Oak Ridge National Laboratory]] (2010).
**118. [[oganesson]], Og, after [[Yuri Oganessian]], who led the JINR team in its discovery of elements 114 to 118 (2002).

==Superheavy elements==
{{periodic table (micro)|title=Superheavy elements<br/>in the [[periodic table]]|caption=''Z''&nbsp;>&nbsp;103 (Lr)|mark=Rf,Db,Sg,Bh,Hs,Mt,Ds,Rg,Cn,Nh,Fl,Mc,Lv,Ts,Og}}

{{main|Superheavy element}}

'''Superheavy elements''', (also known as ''superheavies'', or ''superheavy atoms'', commonly abbreviated '''SHE''') usually refer to the transactinide elements beginning with [[rutherfordium]] (atomic number 104). (Lawrencium, the first 6d element, is sometimes but not always included as well.) They have only been made artificially and currently serve no practical purpose because their short half-lives cause them to decay after a very short time, ranging from a few hours to just milliseconds, which also makes them extremely hard to study.<ref name="She">{{cite journal|last1=Heenen|first1=Paul-Henri|last2=Nazarewicz|first2=Witold|author-link2=Witold Nazarewicz|year=2002|title=Quest for superheavy nuclei|url=https://www.europhysicsnews.org/articles/epn/pdf/2002/01/epn02102.pdf|url-status=live|journal=Europhysics News|volume=33|issue=1|pages=5–9|bibcode=2002ENews..33....5H|doi=10.1051/epn:2002102|archive-url=https://web.archive.org/web/20180720100024/https://www.europhysicsnews.org/articles/epn/pdf/2002/01/epn02102.pdf|archive-date=20 July 2018|doi-access=free}}</ref><ref name="Green">{{cite journal|last1=Greenwood|first1=Norman N.|year=1997|title=Recent developments concerning the discovery of elements 100–111|url=https://old.iupac.org/publications/pac/1997/pdf/6901x0179.pdf|url-status=live|journal=[[Pure and Applied Chemistry]]|volume=69|issue=1|pages=179–184|doi=10.1351/pac199769010179|s2cid=98322292|archive-url=https://web.archive.org/web/20180721170653/https://old.iupac.org/publications/pac/1997/pdf/6901x0179.pdf|archive-date=21 July 2018}}</ref>

Superheavies have all been created since the latter half of the 20th century and are continually being created during the 21st century as technology advances. They are created through the bombardment of elements in a particle accelerator, in quantities on the atomic scale, and no method of mass creation has been found.<ref name="She"/>

==Applications==

Transuranic elements may be used to synthesize superheavy elements.<ref>{{cite journal|last=Lougheed|first=R. W.|author2=Landrum, J. H.|author3=Hulet, E. K.|author4=Wild, J. F.|author5=Dougan, R. J.|author6=Dougan, A. D.|author7=Gäggeler, H.|author8=Schädel, M.|author9=Moody, K. J.|display-authors=1|date=1985|title=Search for superheavy elements using <sup>48</sup>Ca + <sup>254</sup>Es<sup>g</sup> reaction|journal=[[Physical Review C]]|volume=32|issue=5|pages=1760–1763|bibcode=1985PhRvC..32.1760L|doi=10.1103/PhysRevC.32.1760|author10=Gregorich, K. E.|author11=Seaborg, G. T.|pmid=9953034}}</ref> Elements of the island of stability have potentially important military applications, including the development of compact nuclear weapons.<ref>{{cite book|url=https://cryptome.org/2014/06/wmd-4th-gen-quest.pdf|title=The Physical Principles of Thermonuclear Explosives, Intertial Confinement Fusion, and the Quest for Fourth Generation Nuclear Weapons|last1=Gsponer|first1=André|last2=Hurni|first2=Jean-Pierre|publisher=International Network of Engineers and Scientists Against Proliferation|year=1997|isbn=978-3-933071-02-6|pages=110–115|archive-url=https://web.archive.org/web/20180606134706/https://cryptome.org/2014/06/wmd-4th-gen-quest.pdf|archive-date=6 June 2018|url-status=live}}</ref> The potential everyday applications are vast; [[americium]] is used in devices such as [[smoke detectors]] and [[spectrometers]].<ref>{{citation |url=http://www.uic.com.au/nip35.htm |archive-url=http://webarchive.loc.gov/all/20020911070229/http%3A//www%2Euic%2Ecom%2Eau/nip35%2Ehtm |archive-date= 11 September 2002 |title=Smoke Detectors and Americium |work=Nuclear Issues Briefing Paper |volume=35 |date=May 2002 |access-date=2015-08-26}}</ref><ref>[http://www.nndc.bnl.gov/nudat2/indx_dec.jsp Nuclear Data Viewer 2.4], NNDC</ref>

==See also==
*[[Bose–Einstein condensate]] (also known as ''superatom'')
*[[Minor actinide]]
*[[Deep geological repository]], a place to deposit transuranic waste

==References==
{{notelist}}
{{reflist|30em}}

==Further reading==
*Eric Scerri, A Very Short Introduction to the Periodic Table, Oxford University Press, Oxford, 2011.
*[http://www.scitopics.com/The_Superheavy_Elements.html The Superheavy Elements]
*[http://alsos.wlu.edu/qsearch.aspx?browse=science/Transuranium+Elements Annotated bibliography for the transuranic elements] from the Alsos Digital Library for Nuclear Issues.
*[https://web.archive.org/web/20070503140615/http://web.fccj.org/~ethall/uranium/uranium.htm Transuranium elements]
*[http://www.transfermium.net/ Super Heavy Elements network official website] (network of the European integrated infrastructure initiative EURONS)
*[http://pubs.acs.org/cen/80th/darmstadtium.html Darmstadtium and beyond]
* Christian Schnier, Joachim Feuerborn, Bong-Jun Lee: Traces of transuranium elements in terrestrial minerals? ([https://web.archive.org/web/20211005201142/ftp://ftp.hzg.de/pub/schnier/1-Transuranium%20.pdf Online], PDF-Datei, 493&nbsp;kB)
* Christian Schnier, Joachim Feuerborn, Bong-Jun Lee: The search for super heavy elements (SHE) in terrestrial minerals using XRF with high energy synchrotron radiation. ([https://web.archive.org/web/20211005201119/ftp://ftp.hzg.de/pub/schnier/2-SHE.pdf Online], PDF-Datei, 446&nbsp;kB)

{{Navbox periodic table}}
<!-- Please cite sources to help with the encyclopedia's general verifiability concerns.

Tips for referencing: see: [[WP:CITET]]. Thanks! -->

{{Authority control}}

{{DEFAULTSORT:Transuranium Element}}
[[Category:Nuclear physics]]
[[Category:Sets of chemical elements]]