Editing Promethium (section)

==History==

===Searches for element 61===
In 1902, Czech chemist [[Bohuslav Brauner]] found out that the differences in properties between neodymium and samarium were the largest between any two consecutive lanthanides in the sequence then known; as a conclusion, he suggested there was an element with intermediate properties between them.<ref name="61a">{{cite journal|title =A Revised Periodic Table: With the Lanthanides Repositioned|journal=Foundations of Chemistry|volume=7|issue=3|year=2005|doi=10.1007/s10698-004-5959-9|pages=203–233|first=Michael|last=Laing|s2cid=97792365}}</ref> This prediction was supported in 1914 by [[Henry Moseley]] who, having discovered that [[atomic number]] was an experimentally measurable property of elements, found that a few atomic numbers had no known corresponding elements: the gaps were [[Technetium|43]], 61, [[Hafnium|72]], [[Rhenium|75]], [[Astatine|85]], and [[Francium|87]].<ref>{{cite book|title=Atomic and Nuclear Physics: An Introduction in S.I. Units|edition=2nd|year=1968|publisher=Van Nostrand|page=109|last1=Littlefield |first1=Thomas Albert|last2=Thorley|first2=Norman}}</ref> With the knowledge of a gap in the periodic table several groups started to search for the predicted element among other rare earths in the natural environment.{{sfn|Lavrukhina|Pozdnyakov|1966|p=108}}<ref name="Weeks">{{cite book |last1=Weeks |first1=Mary Elvira |title=The discovery of the elements |date=1956 |publisher=Journal of Chemical Education |location=Easton, PA |url=https://archive.org/details/discoveryoftheel002045mbp |edition=6th }}</ref><ref name="Marshall">{{cite journal |last1=Marshall |first1=James L. Marshall |last2=Marshall |first2=Virginia R. Marshall |title=Rediscovery of the elements: The Rare Earths–The Last Member |journal=The Hexagon |date=2016 |pages=4–9 |url=https://chemistry.unt.edu/sites/default/files/users/owj0001/rare%20earths%20III_0.pdf |access-date=30 December 2019 |archive-date=27 November 2021 |archive-url=https://web.archive.org/web/20211127115101/https://chemistry.unt.edu/sites/default/files/users/owj0001/rare%20earths%20III_0.pdf |url-status=dead }}</ref>

The first claim of a discovery was published by Luigi Rolla and Lorenzo Fernandes of [[Florence]], Italy. After separating a mixture of a few rare earth elements nitrate concentrate from the [[Brazil]]ian mineral [[monazite]] by fractionated crystallization, they yielded a solution containing mostly samarium. This solution gave x-ray spectra attributed to samarium and element 61. In honor of their city, they named element 61 "florentium". The results were published in 1926, but the scientists claimed that the experiments were done in 1924.<ref>{{cite journal|doi=10.1002/zaac.19261570129|title=Über das Element der Atomnummer 61|year=1926|last1=Rolla|first1=Luigi|last2=Fernandes|first2=Lorenzo|journal=Zeitschrift für Anorganische und Allgemeine Chemie|volume=157|issue=1 |pages=371–381|language=de}}</ref><ref>{{cite journal|doi=10.1038/120014c0|title=Florentium or Illinium?|year=1927|author=Noyes, W. A.|journal=Nature |volume=120|pages=14|issue=3009|bibcode=1927Natur.120...14N|s2cid=4094131|doi-access=free}}</ref><ref>{{cite journal|doi=10.1038/119637a0|title=Florentium or Illinium?|year=1927|author=Rolla, L.|journal=Nature |volume=119|pages=637|last2=Fernandes|first2=L.|issue=3000|bibcode=1927Natur.119..637R|s2cid=4127574}}</ref><ref>{{cite journal|doi=10.1002/zaac.19281690128|title=Florentium. II|year=1928 |author=Rolla, Luigi|journal=Zeitschrift für Anorganische und Allgemeine Chemie|volume=169|pages=319–320|last2=Fernandes|first2=Lorenzo|issue=1 }}</ref><ref>{{cite journal |doi=10.1002/zaac.19271630104|title=Florentium|year=1927|author=Rolla, Luigi|journal=Zeitschrift für Anorganische und Allgemeine Chemie|volume=163 |pages=40–42|last2=Fernandes |first2=Lorenzo|issue=1 }}</ref><ref>{{cite journal|doi=10.1002/zaac.19271600119|title=Über Das Element der Atomnummer 61 (Florentium)|year=1927|author=Rolla, Luigi|journal=Zeitschrift für Anorganische und Allgemeine Chemie|volume=160|pages=190–192|last2=Fernandes|first2=Lorenzo|issue=1 }}</ref> Also in 1926, a group of scientists from the [[University of Illinois at Urbana–Champaign]], Smith Hopkins and Len Yntema published the discovery of element 61. They named it "illinium", after the university.<ref>{{cite journal |doi=10.1038/117792a0|title=The Element of Atomic Number 61; Illinium|year=1926|author=Harris, J. A.|journal=Nature|volume=117|pages=792|last2=Yntema|first2=L. F.|last3=Hopkins|first3=B. S.|issue=2953 |bibcode=1926Natur.117..792H|doi-access=free}}</ref><ref>{{cite journal|doi=10.1038/118084b0|title=The New Element of Atomic Number 61: Illinium|year=1926|author=Brauner, Bohuslav |journal=Nature|volume=118|pages=84–85|issue=2959|bibcode=1926Natur.118...84B|s2cid=4089909}}</ref><ref>{{cite journal|doi=10.1007/BF01490264|title=Über das Element 61 (Illinium)|year=1926 |author=Meyer, R. J.|journal=Naturwissenschaften|volume=14|pages=771|last2=Schumacher|first2=G.|last3=Kotowski|first3=A.|bibcode=1926NW.....14..771M|issue=33|s2cid=46235121}}</ref> Both of these reported discoveries were shown to be erroneous because the spectrum line that "corresponded" to element 61 was identical to that of [[didymium]]; the lines thought to belong to element 61 turned out to belong to a few impurities (barium, chromium, and platinum).{{sfn|Lavrukhina|Pozdnyakov|1966|p=108}}

<!----REFS!!!--->In 1934, [[Josef Mattauch]] finally formulated the [[Mattauch isobar rule|isobar rule]]. One of the indirect consequences of this rule was that element 61 was unable to form stable isotopes.{{sfn|Lavrukhina|Pozdnyakov|1966|p=108}}<ref name="rare-earth-handbook">{{cite book|last1=Thyssen|first1=Pieter|last2=Binnemans|first2=Koen|editor1-last=Gschneider|editor1-first=Karl A. Jr.|editor2-last=Bünzli|editor2-first=Jean-Claude|editor3-last=Pecharsky|editor3-first=Vitalij K.|chapter=Accommodation of the Rare Earths in the Periodic Table: A Historical Analysis|title=Handbook on the Physics and Chemistry of Rare Earths|year=2011|page=63|publisher=Elsevier|location=Amsterdam|isbn=978-0-444-53590-0|oclc=690920513|chapter-url=https://books.google.com/books?id=8SstnPFSzb0C&pg=PA66|access-date=2013-04-25}}</ref> From 1938, a nuclear experiment was conducted by H. B. Law et al. at the [[Ohio State University]]. Nuclides were produced in 1941 which were not radioisotopes of neodymium or samarium, and the name "cyclonium" was proposed, but there was a lack of chemical proof that element 61 was produced and the discovery was not largely recognized.{{sfn|Emsley|2011|p=428}}<ref>{{cite book |first1=Marco |last1=Fontani |first2=Mariagrazia |last2=Costa |first3=Mary Virginia |last3=Orna |trans-title=The Periodic Table's Shadow Side |title=The Lost Elements |publisher=Oxford University Press |place=New York |year=2015 |orig-year=2014 |isbn=978-0-19-938334-4 |pages=302–303}}</ref>

===Discovery and synthesis of promethium metal===
Promethium was first produced and characterized at [[Oak Ridge National Laboratory]] (Clinton Laboratories at that time) in 1945 by [[Jacob A. Marinsky]], [[Lawrence E. Glendenin]] and [[Charles D. Coryell]] by separation and analysis of the fission products of [[uranium]] fuel irradiated in the [[X-10 Graphite Reactor|graphite reactor]]; however, being too busy with military-related research during [[World War II]], they did not announce their discovery until 1947.<ref name="Marinsky">{{cite journal |doi=10.1021/ja01203a059 |year=1947 |last1=Marinsky |first1=J. A. |last2=Glendenin |first2=L. E. |last3=Coryell |first3=C. D. |journal=Journal of the American Chemical Society |volume=69 |issue=11 |pages=2781–5 |pmid=20270831 |title=The chemical identification of radioisotopes of neodymium and of element 61|bibcode=1947JAChS..69.2781M |hdl=2027/mdp.39015086506477 |hdl-access=free }}</ref><ref>{{cite journal |year=2003 |title=Discovery of Promethium |journal=Oak Ridge National Laboratory Review |volume=36 |issue=1 |url= http://www.ornl.gov/info/ornlreview/v36_1_03/article_02.shtml |access-date=2006-09-17 |url-status=dead |archive-url= https://web.archive.org/web/20150706071605/http://www.ornl.gov/info/ornlreview/v36_1_03/article_02.shtml |archive-date=2015-07-06}}<br />{{cite journal |year=2003 |title=Discovery of Promethium |journal=Oak Ridge National Laboratory Review |volume=36 |issue=1 |page=3 |url=https://www.ornl.gov/sites/default/files/ORNL%20Review%20v36n1%202003.pdf#page=5 |access-date=2018-06-17}}</ref> The original proposed name was "clintonium", after the laboratory where the work was conducted; however, the name "prometheum" was suggested by Grace Mary Coryell, the wife of one of the discoverers.{{sfn|Emsley|2011|p=428}} It is derived from [[Prometheus]], the Titan in [[Greek mythology]] who stole fire from Mount Olympus and brought it down to humans{{sfn|Emsley|2011|p=428}} and symbolizes "both the daring and the possible misuse of the mankind intellect".<ref>{{cite book|title=Inorganic Chemistry|publisher=John Wiley and Sons|page=1694|first1=Egon|last1=Wiberg|first2=Nils|last2=Wiberg |first3=Arnold Frederick|last3=Holleman|year=2001|isbn=978-0-12-352651-9}}</ref> The spelling was then changed to "promethium", as this was in accordance with most other metals.{{sfn|Emsley|2011|p=428}}

<gallery widths="180" heights="200" class="center">
  File:Jacob A Marinsky.jpg|[[Jacob A. Marinsky]]
  File:Larry E Glendenin.jpg|[[Lawrence E. Glendenin]]
  File:Charles D. Coryell M.I.T. May 1947.png|[[Charles D. Coryell]]
</gallery>

In 1963, promethium(III) fluoride was used to make promethium metal. Provisionally purified from impurities of samarium, neodymium, and americium, it was put into a [[tantalum]] crucible which was located in another tantalum crucible; the outer crucible contained lithium metal (10 times excess compared to promethium).{{sfn|Emsley|2011|p=429}}{{sfn|Lavrukhina|Pozdnyakov|1966|p=123}} After creating a vacuum, the chemicals were mixed to produce promethium metal:

:PmF<sub>3</sub> + 3&nbsp;Li → Pm + 3&nbsp;LiF

The promethium sample produced was used to measure a few of the metal's properties, such as its [[melting point]].{{sfn|Lavrukhina|Pozdnyakov|1966|p=123}}

In 1963, ion-exchange methods were used at ORNL to prepare about ten grams of promethium from nuclear reactor fuel processing wastes.<ref name="CRCel" /><ref>{{cite journal|doi =10.1007/BF02037697|title =Chemical study on the separation and purification of promethium-147|year =1989|author =Lee, Chung-Sin|journal =Journal of Radioanalytical and Nuclear Chemistry|volume =130|pages =21–37|last2 =Wang|first2 =Yun-Ming|last3 =Cheng|first3 =Wu-Long|last4 =Ting|first4 =Gann|issue =1|bibcode =1989JRNC..130...21L|s2cid =96599441}}</ref><ref>{{cite web |url= http://www.ornl.gov/info/reports/1962/3445605484259.pdf |title= Ion exchange purification of promethium-147 and its separation from americium-241, with diethylenetriaminepenta-acetic acid as the eluant |author= Orr, P. B. |publisher= Oak Ridge National Laboratory |year= 1962 |access-date= 2011-01-31 |archive-url= https://web.archive.org/web/20110629124017/http://www.ornl.gov/info/reports/1962/3445605484259.pdf |archive-date= 2011-06-29 |url-status= dead }}<br />{{cite report |url=https://www.osti.gov/servlets/purl/4819080/ |title=Ion exchange purification of promethium-147 and its separation from americium-241, with diethylenetriaminepenta-acetic acid as the eluant |author=Orr, P. B. |publisher=Oak Ridge National Laboratory |year=1962 |doi=10.2172/4819080 |access-date=2018-06-17 |hdl=2027/mdp.39015077313933 |osti=4819080 |hdl-access=free }}</ref>

Promethium can be either recovered from the byproducts of uranium fission or produced by bombarding <sup>146</sup>Nd with [[neutron]]s, turning it into <sup>147</sup>Nd, which decays into [[promethium-147|<sup>147</sup>Pm]] through beta decay with a half-life of 11 days.<ref>{{cite web|url=http://education.jlab.org/itselemental/ele061.html|title=The Element Promethium|last=Gagnon|first=Steve|work=Jefferson Lab|publisher=Science Education|access-date=26 February 2012}}</ref>