Editing Halogen (section)

== History ==
The fluorine mineral [[fluorospar|fluorspar]] was known as early as 1529. It is believed to be found in the foot bones of early dinosaurs.{{citation needed|date=March 2025}} Early chemists realized that fluorine compounds contain an undiscovered element, but were unable to isolate it. In 1860, [[George Gore (chemist)|George Gore]], an English chemist, ran a current of electricity through [[hydrofluoric acid]] and probably produced fluorine, but he was unable to prove his results at the time.{{cn|date=November 2023}} In 1886, [[Henri Moissan]], a chemist in Paris, performed [[electrolysis]] on [[potassium bifluoride]] dissolved in anhydrous [[hydrogen fluoride]], and successfully isolated fluorine.<ref name="Nature's Building Blocks">{{cite book|last=Emsley|first=John|title=Nature's Building Blocks|year=2011|publisher=OUP Oxford |isbn= 978-0199605637}}</ref>

[[Hydrochloric acid]] was known to [[alchemy|alchemists]] and early chemists. However, elemental chlorine was not produced until 1774, when [[Carl Wilhelm Scheele]] heated hydrochloric acid with [[manganese dioxide]]. Scheele called the element "dephlogisticated muriatic acid", which is how chlorine was known for 33 years. In 1807, [[Humphry Davy]] investigated chlorine and discovered that it is an actual element. Chlorine gas was used as a [[poisonous gas]] during [[World War I]]. It displaced oxygen in contaminated areas and replaced common oxygenated air with the toxic chlorine gas. The gas would burn human tissue externally and internally, especially the lungs, making breathing difficult or impossible depending on the level of contamination.<ref name = "Nature's Building Blocks"/>

Bromine was discovered in the 1820s by [[Antoine Jérôme Balard]]. Balard discovered bromine by passing chlorine gas through a sample of [[brine]]. He originally proposed the name ''muride'' for the new element, but the [[French Academy]] changed the element's name to bromine.<ref name = "Nature's Building Blocks"/>

Iodine was discovered by [[Bernard Courtois]], who was using [[seaweed]] ash as part of a process for [[saltpeter]] manufacture. Courtois typically boiled the seaweed ash with water to generate [[potassium chloride]]. However, in 1811, Courtois added sulfuric acid to his process and found that his process produced purple fumes that condensed into black crystals. Suspecting that these crystals were a new element, Courtois sent samples to other chemists for investigation. Iodine was proven to be a new element by [[Joseph Gay-Lussac]].<ref name = "Nature's Building Blocks"/>

In 1931, [[Fred Allison]] claimed to have discovered element 85 with a [[Magneto-optic effect|magneto-optical machine]], and named the element Alabamine, but was mistaken. In 1937, [[Rajendralal De]] claimed to have discovered element 85 in minerals, and called the element dakine, but he was also mistaken. An attempt at discovering element 85 in 1939 by [[Horia Hulubei]] and [[Yvette Cauchois]] via [[spectroscopy]] was also unsuccessful, as was an attempt in the same year by [[Walter Minder]], who discovered an iodine-like element resulting from [[beta decay]] of [[polonium]]. Element 85, now named [[astatine]], was produced successfully in 1940 by [[Dale R. Corson]], [[K.R. Mackenzie]], and [[Emilio G. Segrè]], who bombarded [[bismuth]] with [[alpha particle]]s.<ref name = "Nature's Building Blocks"/>

In 2010, a team led by nuclear physicist [[Yuri Oganessian]] involving scientists from the [[JINR]], [[Oak Ridge National Laboratory]], [[Lawrence Livermore National Laboratory]], and [[Vanderbilt University]] successfully bombarded berkelium-249 atoms with calcium-48 atoms to make tennessine.<ref name="117s">{{cite journal|last1=Oganessian |first1=Yu.Ts. |author-link1=Yuri Oganessian |last2=Abdullin |first2=F.Sh. |last3=Bailey |first3=P.D. |last4=Benker |first4=D.E. |last5=Bennett |first5=M.E. |last6=Dmitriev |first6=S.N. |last7=Ezold |first7=J.G. |last8=Hamilton |first8=J.H. |last9=Henderson |first9=R.A. |first10=M.G. |last10=Itkis |first11=Yuri V. |last11=Lobanov |first12=A.N. |last12=Mezentsev |first13=K. J. |last13=Moody |first14=S.L. |last14=Nelson |first15=A.N. |last15=Polyakov | first16=C.E. |last16=Porter |first17=A.V. |last17=Ramayya |first18=F.D. |last18=Riley |first19=J.B. |last19=Roberto |first20=M. A. |last20=Ryabinin | first21=K.P. |last21=Rykaczewski |first22=R.N. |last22=Sagaidak | first23=D.A. |last23=Shaughnessy |first24=I.V. |last24=Shirokovsky |first25=M.A. |last25=Stoyer |first26=V.G. |last26=Subbotin | first27=R. |last27=Sudowe |first28=A.M. |last28=Sukhov |first29=Yu.S. |last29=Tsyganov |first30=Vladimir K. |last30=Utyonkov |first31=A.A. |last31=Voinov |first32=G.K. |last32=Vostokin | first33=P.A. |last33=Wilk |display-authors=6 |title=Synthesis of a new element with atomic number {{nowrap|{{mvar|Z}} {{=}} 117}} |year=2010 |journal=Physical Review Letters |volume=104 |issue=14 |page=142502 |doi=10.1103/PhysRevLett.104.142502 |pmid=20481935 |bibcode=2010PhRvL.104n2502O |s2cid=3263480 |doi-access=free }}</ref>  

=== Etymology ===
In 1811, the German chemist [[Johann Schweigger]] proposed that the name "halogen" – meaning "salt producer", from αλς [hals] "salt" and γενειν [genein] "to beget" – replace the name "chlorine", which had been proposed by the English chemist [[Humphry Davy]].<ref>{{cite journal|last1=Schweigger|first1=J.S.C.|title=Nachschreiben des Herausgebers, die neue Nomenclatur betreffend|journal=Journal für Chemie und Physik|date=1811|volume=3|issue=2|pages=249–255|url=https://babel.hathitrust.org/cgi/pt?id=njp.32101076802287;view=1up;seq=295|trans-title=Postscript of the editor concerning the new nomenclature|language=de}}  On p. 251, Schweigger proposed the word "halogen":  ''"Man sage dafür lieber mit richter Wortbildung ''Halogen'' (da schon in der Mineralogie durch ''Werner's'' Halit-Geschlecht dieses Wort nicht fremd ist) von αλς ''Salz'' und dem alten γενειν (dorisch γενεν) ''zeugen''."'' (One should say instead, with proper morphology, "halogen" (this word is not strange since [it's] already in mineralogy via Werner's "halite" species) from αλς [als] "salt" and the old γενειν [genein] (Doric γενεν) "to beget".)</ref>  Davy's name for the element prevailed.<ref>{{Cite journal|title=J. S. C. Schweigger: His Romanticism and His Crystal Electrical Theory of Matter|journal=Isis|volume=62|issue=3 |pages=328–338|year=1971|doi=10.1086/350763|jstor=229946|last1=Snelders|first1=H. A. M.|s2cid=170337569}}</ref> However, in 1826, the [[Sweden|Swedish]] [[chemist]] Baron [[Jöns Jacob Berzelius]] proposed the term "halogen" for the elements fluorine, chlorine, and iodine, which produce a [[salt (chemistry)|sea-salt]]-like substance when they form a [[chemical compound|compound]] with an alkaline metal.<ref>In 1826, Berzelius coined the terms ''Saltbildare'' (salt-formers) and ''Corpora Halogenia'' (salt-making substances) for the elements chlorine, iodine, and fluorine.  See:  {{cite journal|last1=Berzelius|first1=Jacob|title=Årsberättelser om Framstegen i Physik och Chemie| journal=Arsb. Vetensk. Framsteg |trans-title=Annual Report on Progress in Physics and Chemistry|date=1826|publisher=P.A. Norstedt & Söner|location=Stockholm, Sweden|volume=6|page=187|url=https://babel.hathitrust.org/cgi/pt?id=hvd.32044092556919;view=1up;seq=195|language=sv}} From p. 187: ''"De förre af dessa, d. ä. ''de electronegativa'', dela sig i tre klasser: 1) den första innehåller kroppar, som förenade med de electropositiva, omedelbart frambringa salter, hvilka jag derför kallar ''Saltbildare'' (Corpora Halogenia). Desse utgöras af chlor, iod och fluor *)."'' (The first of them [i.e., elements], the electronegative [ones], are divided into three classes:  1) The first includes substances which, [when] united with electropositive [elements], immediately produce salts, and which I therefore name "salt-formers" (salt-producing substances).  These are chlorine, iodine, and fluorine *).)</ref><ref>The word "halogen" appeared in English as early as 1832 (or earlier).  See, for example: Berzelius, J.J. with A.D. Bache, trans., (1832) [https://books.google.com/books?id=eWsWAAAAYAAJ&pg=RA1-PA248 "An essay on chemical nomenclature, prefixed to the treatise on chemistry,"] ''The American Journal of Science and Arts'', '''22''': 248–276 ; see, for example [https://books.google.com/books?id=eWsWAAAAYAAJ&pg=RA1-PA263 p. 263.]</ref>

The English names of these elements all have the ending [[-ine]]. Fluorine's name comes from the [[Latin]] word ''fluere'', meaning "to flow", because it was derived from the mineral [[fluorite]], which was used as a [[Flux (metallurgy)|flux]] in metalworking. Chlorine's name comes from the [[Greek language|Greek]] word ''chloros'', meaning "greenish-yellow". Bromine's name comes from the Greek word ''bromos'', meaning "stench". Iodine's name comes from the Greek word ''iodes'', meaning "violet". Astatine's name comes from the Greek word ''astatos'', meaning "unstable".<ref name = "Nature's Building Blocks"/> Tennessine is named after the US state of [[Tennessee]], where it was synthesized.