Editing Francium (section)

==Applications==
Due to its instability and rarity, there are no commercial applications for francium.<ref>{{cite web| last = Winter| first = Mark| title = Uses| work = Francium| publisher = The University of Sheffield|url = http://www.webelements.com/webelements/elements/text/Fr/uses.html| access-date = March 25, 2007}}</ref><ref name="nbb">{{cite book| last = Emsley|url=https://books.google.com/books?id=Yhi5X7OwuGkC&pg=PA151| first = John| title = Nature's Building Blocks| publisher = Oxford University Press| date = 2001| location = Oxford| pages = 151–153| isbn = 978-0-19-850341-5}}</ref><ref name="elemental">{{cite web| last = Gagnon| first = Steve| title = Francium| publisher = Jefferson Science Associates, LLC| url = http://education.jlab.org/itselemental/ele087.html | access-date = April 1, 2007}}</ref><ref name="nostrand332" /> It has been used for research purposes in the fields of [[chemistry]]<ref name="bio">{{cite journal | last1 = Haverlock |first1 = T. J. |pmid = 12553788 |doi= 10.1021/ja0255251|title = Selectivity of calix[4]arene-bis(benzocrown-6) in the complexation and transport of francium ion |journal = J Am Chem Soc|date = 2003|volume=125|pages=1126–7| last2 = Mirzadeh| first2 = S.|last3 = Moyer| first3 = B. A.|issue = 5|bibcode = 2003JAChS.125.1126H }}</ref>
and of [[atom|atomic structure]]. Its use as a potential diagnostic aid for various [[cancer]]s has also been explored,<ref name="andyscouse" /> but this application has been deemed impractical.<ref name="nbb" />

Francium's ability to be synthesized, trapped, and cooled, along with its relatively simple [[atom|atomic structure]], has made it the subject of specialized [[spectroscopy]] experiments. These experiments have led to more specific information regarding [[energy level]]s and the [[coupling constant]]s between [[subatomic particle]]s.<ref>{{cite journal| last = Gomez| first = E.|author2=Orozco, L A |author3=Sprouse, G D | s2cid = 15917603| title = Spectroscopy with trapped francium: advances and perspectives for weak interaction studies| journal = Rep. Prog. Phys.| volume = 69| issue = 1| pages = 79–118| date = November 7, 2005|doi = 10.1088/0034-4885/69/1/R02|bibcode = 2006RPPh...69...79G}}</ref> Studies on the light emitted by [[Optical tweezers|laser-trapped]] francium-210 ions have provided accurate data on transitions between atomic energy levels which are fairly similar to those predicted by [[quantum mechanics|quantum theory]].<ref>{{cite journal|last = Peterson|first = I.|title = Creating, cooling, trapping francium atoms|journal = Science News|date = May 11, 1996|url = http://www.sciencenews.org/pages/pdfs/data/1996/149-19/14919-06.pdf|access-date = September 11, 2001|volume = 149|issue = 19|pages = 294|doi = 10.2307/3979560|jstor = 3979560|archive-date = July 27, 2020|archive-url = https://web.archive.org/web/20200727014700/https://www.sciencenews.org/pages/pdfs/data/1996/149-19/14919-06.pdf|url-status = dead}}</ref> Francium is a prospective candidate for searching for [[CP violation]].<ref>{{cite journal | last1=Osika | first1=Yuliya | last2=Meniailava | first2=Darya | last3=Shundalau | first3=Maksim | title=Relativistic coupled cluster study on the spectroscopic and radiative properties of the KFr molecule and modeling of the transport properties of potassium–francium dilute gas medium | journal=Journal of Quantitative Spectroscopy and Radiative Transfer | publisher=Elsevier BV | volume=321 | year=2024 | issn=0022-4073 | doi=10.1016/j.jqsrt.2024.108996 | page=108996| bibcode=2024JQSRT.32108996O }}</ref>