Editing Group 5 element (section)

== History ==

[[File:'Andrés Manuel de Río' (1825) by Rafael Ximeno y Planes - Museo Tolsá - Palacio de Minería - Mexico 2024.jpg|thumb|right|Andrés Manuel del Río, the discoverer of vanadium]]

''Group 5'' is the new IUPAC name for this group; the old style name was ''group VB'' in the old US system (CAS) or ''group VA'' in the European system (old IUPAC). Group 5 must not be confused with the group with the old-style group crossed names of either ''VA'' (US system, CAS) or ''VB'' (European system, old IUPAC); that group is now called the [[pnictogen]]s or group 15.<ref name="Fluck 1988">{{cite journal |last1=Fluck |first1=E. |year=1988 |title=New Notations in the Periodic Table |url=http://www.iupac.org/publications/pac/1988/pdf/6003x0431.pdf |journal=[[Pure and Applied Chemistry|Pure Appl. Chem.]] |publisher=[[International Union of Pure and Applied Chemistry|IUPAC]] |volume=60 |issue=3 |pages=431–436 |doi=10.1351/pac198860030431 |s2cid=96704008 |access-date=24 March 2012}}</ref>

=== Vanadium ===

Vanadium was [[discovery of the chemical elements|discovered]] in 1801 by the Spanish mineralogist [[Andrés Manuel del Río]]. Del Río extracted the element from a sample of Mexican "brown lead" ore, later named [[vanadinite]]. He found that its salts exhibit a wide variety of colors, and as a result he named the element ''panchromium'' (Greek: παγχρώμιο "all colors"). Later, Del Río renamed the element ''erythronium'' (Greek: ερυθρός "red") because most of the salts turned red upon heating. In 1805, French chemist [[Hippolyte Victor Collet-Descotils]], backed by del Río's friend Baron [[Alexander von Humboldt]], incorrectly declared that del Río's new element was an impure sample of [[chromium]]. Del Río accepted Collet-Descotils' statement and retracted his claim.<ref name="Cintas">{{cite journal|title= The Road to Chemical Names and Eponyms: Discovery, Priority, and Credit|author= Cintas, Pedro|journal= Angewandte Chemie International Edition|volume= 43|issue= 44|date= 2004|pmid= 15376297|doi= 10.1002/anie.200330074|pages= 5888–94}}</ref>

In 1831 Swedish chemist [[Nils Gabriel Sefström]] rediscovered the element in a new oxide he found while working with [[iron ore]]s. Later that year, [[Friedrich Wöhler]] confirmed del Río's earlier work.<ref name="sefs">{{cite journal|title= Ueber das Vanadin, ein neues Metall, gefunden im Stangeneisen von Eckersholm, einer Eisenhütte, die ihr Erz von Taberg in Småland bezieht|first= N. G.|last= Sefström|journal= [[Annalen der Physik und Chemie]]|volume= 97|issue= 1|pages= 43–49|date= 1831|doi= 10.1002/andp.18310970103|bibcode= 1831AnP....97...43S|url= https://zenodo.org/record/1423544}}</ref> Sefström chose a name beginning with V, which had not yet been assigned to any element. He called the element ''vanadium'' after [[Old Norse]] ''[[list of names of Freyja|Vanadís]]'' (another name for the [[Norse mythology|Norse]] [[Vanir]] goddess [[Freyja]], whose attributes include beauty and fertility), because of the many beautifully colored [[chemical compound]]s it produces.<ref name="sefs" /> In 1831, the geologist [[George William Featherstonhaugh]] suggested that vanadium should be renamed ''rionium'' after del Río, but this suggestion was not followed.<ref>{{cite journal |journal= The Monthly American Journal of Geology and Natural Science |first= George William|last= Featherstonhaugh |title=New Metal, provisionally called Vanadium |year= 1831|page=69 |url= https://archive.org/stream/monthlyamericanj11831phil#page/68/mode/2up/search/rionium}}</ref><!--Featherstonhaugh, the editor of the journal cited, comments on a letter from Berzelious to [[Pierre Louis Dulong]]-->

=== Niobium and tantalum ===

[[File:Charles Hatchett. Soft-ground etching by F. C. Lewis after T Wellcome V0002614 (cropped).jpg|thumb|right|Charles Hatchett, the discover of niobium]]

Niobium was [[Discovery of the chemical elements|identified]] by English chemist [[Charles Hatchett]] in 1801.<ref name="Hatchett_1802a">{{cite journal|last=Hatchett|first=Charles|author-link=Charles Hatchett|year=1802|url=https://books.google.com/books?id=c-Q_AAAAYAAJ&pg=PA49|title=An analysis of a mineral substance from North America, containing a metal hitherto unknown|journal=Philosophical Transactions of the Royal Society of London|volume=92|pages=49–66|jstor=107114|doi=10.1098/rspl.1800.0045|doi-access=free|access-date=15 July 2016|archive-date=3 May 2016|archive-url=https://web.archive.org/web/20160503233004/https://books.google.com/books?id=c-Q_AAAAYAAJ&pg=PA49|url-status=live|url-access=subscription}}</ref><ref name="Hatchett_1802b">{{Citation |last=Hatchett |first=Charles |author-link=Charles Hatchett |year=1802 |title=Outline of the Properties and Habitudes of the Metallic Substance, lately discovered by Charles Hatchett, Esq. and by him denominated Columbium |journal=[[Journal of Natural Philosophy, Chemistry, and the Arts]] |volume=I (January) |pages=32–34 |url=https://books.google.com/books?id=ylZwOmyBA7IC&pg=PA32 |postscript=. |access-date=13 July 2017 |archive-date=24 December 2019 |archive-url=https://web.archive.org/web/20191224164852/https://books.google.com/books?id=ylZwOmyBA7IC&pg=PA32 |url-status=live }}</ref><ref name="Hatchett_1802c">{{cite journal |last=Hatchett |first=Charles |author-link=Charles Hatchett |year=1802 |title=Eigenschaften und chemisches Verhalten des von Charles Hatchett entdeckten neuen Metalls, Columbium |trans-title=Properties and chemical behavior of the new metal, columbium, (that was) discovered by Charles Hatchett |language=de |journal=[[Annalen der Physik]] |volume=11 |issue=5 |pages=120–122 |url=https://books.google.com/books?id=wSYwAAAAYAAJ&pg=PA120 |doi=10.1002/andp.18020110507 |bibcode=1802AnP....11..120H |access-date=15 July 2016 |archive-date=9 May 2016 |archive-url=https://web.archive.org/web/20160509100435/https://books.google.com/books?id=wSYwAAAAYAAJ&pg=PA120 |url-status=live }}</ref> He found a new element in a mineral sample that had been sent to England from [[Connecticut]], United States in 1734 by John Winthrop F.R.S. (grandson of [[John Winthrop the Younger]]) and named the mineral ''columbite'' and the new element ''columbium'' after ''[[Columbia (name)|Columbia]]'',<ref>{{cite journal|title = Reaction of Tantalum, Columbium and Vanadium with Iodine|first = F.|last = Kòrösy|journal = Journal of the American Chemical Society|date = 1939|volume = 61|issue = 4|pages = 838–843|doi = 10.1021/ja01873a018}}</ref> the poetic name for the United States.<ref name="Noyes" /><ref name="1853 Mining Journal">{{cite journal|last=Percival|first=James|title=Middletown Silver and Lead Mines|journal=Journal of Silver and Lead Mining Operations|date=January 1853|volume=1|page=186|url=https://play.google.com/store/books/details?id=MFILAAAAYAAJ&rdid=book-MFILAAAAYAAJ&rdot=1|access-date=24 April 2013|archive-date=3 June 2013|archive-url=https://web.archive.org/web/20130603002528/https://play.google.com/store/books/details?id=MFILAAAAYAAJ&rdid=book-MFILAAAAYAAJ&rdot=1|url-status=live}}</ref><ref>{{cite journal|title = Charles Hatchett FRS (1765–1847), Chemist and Discoverer of Niobium|first = William P.|last = Griffith|author2=Morris, Peter J. T. |journal = Notes and Records of the Royal Society of London|volume = 57|issue = 3|pages = 299–316|date = 2003|jstor = 3557720|doi = 10.1098/rsnr.2003.0216|s2cid = 144857368}}</ref> However, after the 15th Conference of the Union of Chemistry in Amsterdam in 1949, the name niobium was chosen for element 41.<ref name="Contro">{{cite journal |first = Geoff|last = Rayner-Canham|author2=Zheng, Zheng |title = Naming elements after scientists: an account of a controversy|journal = Foundations of Chemistry|volume = 10|issue = 1|date = 2008|doi = 10.1007/s10698-007-9042-1|pages = 13–18|s2cid = 96082444}}</ref> The ''columbium'' discovered by Hatchett was probably a mixture of the new element with tantalum, which was first discovered in 1802 by [[Anders Gustav Ekeberg]].<ref name="Noyes">{{cite book| last = Noyes| first = William Albert| title = A Textbook of Chemistry| publisher = H. Holt & Co.| page = 523| url = https://books.google.com/books?id=UupHAAAAIAAJ&q=columbium+discovered+by+Hatchett+was+a+mixture+of+two+elements&pg=PA523| date = 1918| access-date = 2 November 2020| archive-date = 2 June 2022| archive-url = https://web.archive.org/web/20220602091834/https://books.google.com/books?id=UupHAAAAIAAJ&q=columbium+discovered+by+Hatchett+was+a+mixture+of+two+elements&pg=PA523| url-status = live}}</ref>

[[File:Anders Gustaf Ekeberg.jpg|thumb|right|Anders Gustav Ekeberg, the discoverer of tantalum]]

Subsequently, there was considerable confusion<ref name="Wolla">{{cite journal|title = On the Identity of Columbium and Tantalum|pages = 246–252|journal = Philosophical Transactions of the Royal Society|first = William Hyde|last = Wollaston|author-link = William Hyde Wollaston|doi = 10.1098/rstl.1809.0017| jstor = 107264|volume = 99|date = 1809|s2cid = 110567235}}</ref> over the difference between columbium (niobium) and the closely related tantalum. In 1809, English chemist [[William Hyde Wollaston]] compared the oxides derived from both columbium—columbite, with a density 5.918&nbsp;g/cm{{sup|3}}, and tantalum—[[tantalite]], with a density over 8&nbsp;g/cm{{sup|3}}, and concluded that the two oxides, despite the significant difference in density, were identical; thus he kept the name tantalum.<ref name="Wolla" /> This conclusion was disputed in 1846 by German chemist [[Heinrich Rose]], who argued that there were two different elements in the tantalite sample, and named them after children of [[Tantalus]]: ''niobium'' (from [[Niobe]]) and ''[[pelopium]]'' (from [[Pelops]]).<ref name="Pelop">{{cite journal|title = Ueber die Zusammensetzung der Tantalite und ein im Tantalite von Baiern enthaltenes neues Metall|pages = 317–341|journal = Annalen der Physik|author-link = Heinrich Rose|language = de|first = Heinrich|last = Rose|doi = 10.1002/andp.18441391006|url = http://gallica.bnf.fr/ark:/12148/bpt6k15148n/f327.table|volume = 139|issue = 10|date = 1844|bibcode = 1844AnP...139..317R|access-date = 31 August 2008|archive-date = 20 June 2013|archive-url = https://web.archive.org/web/20130620093605/http://gallica.bnf.fr/ark:/12148/bpt6k15148n/f327.table|url-status = live}}</ref><ref>{{cite journal|title = Ueber die Säure im Columbit von Nordamérika|language = de|pages = 572–577|first = Heinrich|last = Rose|journal = Annalen der Physik|doi = 10.1002/andp.18471460410|url = http://gallica.bnf.fr/ark:/12148/bpt6k15155x/f586.table|date = 1847|volume = 146|issue = 4|author-link = Heinrich Rose|bibcode = 1847AnP...146..572R|access-date = 31 August 2008|archive-date = 11 May 2014|archive-url = https://web.archive.org/web/20140511114909/http://gallica.bnf.fr/ark:/12148/bpt6k15155x/f586.table|url-status = live}}</ref> This confusion arose from the minimal observed differences between tantalum and niobium. The claimed new elements ''pelopium'', ''[[ilmenium]]'', and ''dianium''<ref name="Dianium">{{cite journal|title = Ueber eine eigenthümliche Säure, Diansäure, in der Gruppe der Tantal- und Niob- verbindungen|first = V.|last = Kobell|journal = Journal für Praktische Chemie|volume = 79|issue = 1|pages = 291–303|doi = 10.1002/prac.18600790145|date = 1860|url = https://zenodo.org/record/1427822|access-date = 5 October 2019|archive-date = 5 October 2019|archive-url = https://web.archive.org/web/20191005220552/https://zenodo.org/record/1427822|url-status = live}}</ref> were in fact identical to niobium or mixtures of niobium and tantalum.<ref name="Ilmen">{{cite journal|title = Tantalsäure, Niobsäure, (Ilmensäure) und Titansäure|journal = Fresenius' Journal of Analytical Chemistry|volume = 5|issue = 1|date = 1866|doi = 10.1007/BF01302537|pages = 384–389|author= Marignac, Blomstrand|author2= Deville, H. |author3= Troost, L. |author4= Hermann, R. |s2cid = 97246260}}</ref> Pure tantalum was not produced until 1903.<ref name = "Emsley"/>

=== Dubnium ===

The last element of the group, [[dubnium]], does not occur naturally and so must be synthesized in a laboratory. The first reported detection was by a team at the [[Joint Institute for Nuclear Research]] (JINR), which in 1968 had produced the new element by bombarding an [[americium]]-243 target with a beam of [[neon]]-22 ions, and reported 9.4&nbsp;MeV (with a half-life of 0.1–3 seconds) and 9.7&nbsp;MeV (''t''<sub>1/2</sub>&nbsp;>&nbsp;0.05&nbsp;s) [[alpha decay|alpha activities]] followed by alpha activities similar to those of either <sup>256</sup>103 or <sup>257</sup>103. Based on prior theoretical predictions, the two activity lines were assigned to <sup>261</sup>105 and <sup>260</sup>105, respectively.<ref name="1993 report">{{Cite journal|year=1993|title=Discovery of the Transfermium elements|url=http://s3.documentcloud.org/documents/562229/iupac1.pdf|journal=Pure and Applied Chemistry|volume=65|issue=8|pages=1757|doi=10.1351/pac199365081757|access-date=September 7, 2016|last1=Barber|first1=R. C.|last2=Greenwood|first2=N. N.|author-link2=Norman Greenwood|last3=Hrynkiewicz|first3=A. Z.|display-authors=3|last4=Jeannin|first4=Y. P|last5=Lefort|first5=M|last6=Sakai|first6=M|last7=Ulehla|first7=I|last8=Wapstra|first8=A. H|last9=Wilkinson|first9=D. H|s2cid=195819585}}</ref>

After observing the alpha decays of element 105, the researchers aimed to observe the [[spontaneous fission]] (SF) of the element and study the resulting fission fragments. They published a paper in February 1970, reporting multiple examples of two such activities, with half-lives of 14&nbsp;ms and {{val|2.2|0.5|u=s}}. They assigned the former activity to <sup>242mf</sup>Am{{efn|This notation signifies that the nucleus is a [[nuclear isomer]] that decays via spontaneous fission.}} and ascribed the latter activity to an isotope of element 105. They suggested that it was unlikely that this activity could come from a transfer reaction instead of element 105, because the yield ratio for this reaction was significantly lower than that of the <sup>242mf</sup>Am-producing transfer reaction, in accordance with theoretical predictions. To establish that this activity was not from a (<sup>22</sup>Ne,''x''n) reaction, the researchers bombarded a <sup>243</sup>Am target with <sup>18</sup>O ions; reactions producing <sup>256</sup>103 and <sup>257</sup>103 showed very little SF activity (matching the established data), and the reaction producing heavier <sup>258</sup>103 and <sup>259</sup>103 produced no SF activity at all, in line with theoretical data. The researchers concluded that the activities observed came from SF of element 105.<ref name="1993 report" />

JINR then attempted an experiment to create element 105, published in a report in May 1970. They claimed that they had synthesized more nuclei of element 105 and that the experiment confirmed their previous work. According to the paper, the isotope produced by JINR was probably <sup>261</sup>105, or possibly <sup>260</sup>105.<ref name="1993 report" /> This report included an initial chemical examination: the thermal gradient version of the gas-chromatography method was applied to demonstrate that the chloride of what had formed from the SF activity nearly matched that of [[Niobium(V) chloride|niobium pentachloride]], rather than [[hafnium tetrachloride]]. The team identified a 2.2-second SF activity in a volatile chloride portraying eka-tantalum properties, and inferred that the source of the SF activity must have been element 105.<ref name="1993 report" />

In June 1970, JINR made improvements on their first experiment, using a purer target and reducing the intensity of transfer reactions by installing a [[collimator]] before the catcher. This time, they were able to find 9.1&nbsp;MeV alpha activities with daughter isotopes identifiable as either <sup>256</sup>103 or <sup>257</sup>103, implying that the original isotope was either <sup>260</sup>105 or <sup>261</sup>105.<ref name="1993 report" />

{{multiple image
| footer = Danish nuclear physicist [[Niels Bohr]] and German nuclear chemist [[Otto Hahn]], both proposed as possible namesakes for element 105
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| alt1 = Photo of Niels Bohr
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| image2 = Otto Hahn (Nobel).jpg
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A [[Transfermium Wars|controversy]] erupted on who had discovered the element, which each group suggesting its own name: the Dubna group named the element ''nielsbohrium'' after [[Niels Bohr]], while the Berkeley group named it ''hahnium'' after [[Otto Hahn]].<ref name=transuranium>{{cite book |last1=Hoffman |first1=D. C. |last2=Ghiorso |first2=A. |last3=Seaborg |first3=G. T. |title=The Transuranium People: The Inside Story |year=2000 |pages=369–399 |publisher=Imperial College Press |isbn=978-1-86094-087-3}}</ref> Eventually a joint working party of [[IUPAC]] and [[IUPAP]], the Transfermium Working Group, decided that credit for the discovery should be shared. After various compromises were attempted, where element 105 was called ''kurchatovium'', ''joliotium'' and ''hahnium'', in 1997 IUPAC officially named the element dubnium after Dubna,<ref name=97IUPAC>{{cite journal |doi =10.1351/pac199769122471 |title =Names and symbols of transfermium elements (IUPAC Recommendations 1997) |date =1997 |journal =Pure and Applied Chemistry |volume =69 |issue = 12 |pages =2471–2474|doi-access =free }}</ref><ref name="Emsley" /> and ''nielsbohrium'' was eventually simplified to ''bohrium'' and used for [[bohrium|element 107]].<ref>{{cite journal |last1=Ghiorso |first1=A. |last2=Seaborg |first2=G. T. |last3=Organessian |first3=Yu. Ts. |last4=Zvara |first4=I. |last5=Armbruster |first5=P. |last6=Hessberger |first6=F. P. |last7=Hofmann |first7=S. |last8=Leino |first8=M. |last9=Munzenberg |first9=G. |last10=Reisdorf |first10=W. |last11=Schmidt |first11=K.-H. |year=1993 |title=Responses on 'Discovery of the transfermium elements' by Lawrence Berkeley Laboratory, California; Joint Institute for Nuclear Research, Dubna; and Gesellschaft fur Schwerionenforschung, Darmstadt followed by reply to responses by the Transfermium Working Group |journal=Pure and Applied Chemistry |volume=65 |issue=8 |pages=1815–1824 |doi=10.1351/pac199365081815 |doi-access=free}}</ref><ref name="IUPAC97">{{Cite journal |author=Commission on Nomenclature of Inorganic Chemistry |date=1997 |title=Names and symbols of transfermium elements (IUPAC Recommendations 1997) |url=http://publications.iupac.org/pac/pdf/1997/pdf/6912x2471.pdf |url-status=live |journal=Pure and Applied Chemistry |volume=69 |issue=12 |pages=2471–2474 |doi=10.1351/pac199769122471 |archive-url=https://web.archive.org/web/20211011132719/http://publications.iupac.org/pac/pdf/1997/pdf/6912x2471.pdf |archive-date=2021-10-11 |access-date=2023-07-11}}</ref>