Editing Alkali metal (section)

== History ==
[[File:Petalite.jpg|thumb|alt=A sample of petalite|[[Petalite]], the lithium mineral from which lithium was first isolated]]
Sodium compounds have been known since ancient times; salt ([[sodium chloride]]) has been an important commodity in human activities. While [[potash]] has been used since ancient times, it was not understood for most of its history to be a fundamentally different substance from sodium mineral salts. [[Georg Ernst Stahl]] obtained experimental evidence which led him to suggest the fundamental difference of sodium and potassium salts in 1702,<ref name="1702Suspect">{{cite book|language = de |url= https://books.google.com/books?id=b-ATAAAAQAAJ&pg=PA167 |page= 167|title= Chymische Schriften|last1= Marggraf|first1= Andreas Siegmund |year= 1761}}</ref> and [[Henri-Louis Duhamel du Monceau]] was able to prove this difference in 1736.<ref>{{cite journal |url= http://gallica.bnf.fr/ark:/12148/bpt6k3533j/f73.image.r=Memoires%20de%20l%27Academie%20royale%20des%20Sciences.langEN |journal= Mémoires de l'Académie Royale des Sciences |title= Sur la Base de Sel Marine |last= du Monceau |first= H. L. D. |year= 1736 |pages= 65–68 |language= fr |archive-date= 21 August 2019 |access-date= 2 December 2011 |archive-url= https://web.archive.org/web/20190821202241/https://gallica.bnf.fr/ark%3A/12148/bpt6k3533j/f73.image.r%3DMemoires%20de%20l%27Academie%20royale%20des%20Sciences.langEN |url-status= live }}</ref> The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus [[Antoine Lavoisier]] did not include either alkali in his list of chemical elements in 1789.<ref name="weeks">{{cite journal |doi= 10.1021/ed009p1035|title= The discovery of the elements. IX. Three alkali metals: Potassium, sodium, and lithium |year= 1932|last1= Weeks|first1= Mary Elvira|author-link1=Mary Elvira Weeks|journal= Journal of Chemical Education|volume= 9|issue= 6|page= 1035|bibcode= 1932JChEd...9.1035W}}</ref><ref name="disco">{{cite journal |jstor= 228541|pages= 247–258|last1= Siegfried|first1= R.|title= The Discovery of Potassium and Sodium, and the Problem of the Chemical Elements|volume= 54|issue= 2|journal= Isis|year= 1963|doi= 10.1086/349704|pmid= 14147904|s2cid= 38152048}}</ref>

Pure potassium was first isolated in 1807 in England by [[Humphry Davy]], who derived it from [[caustic potash]] (KOH, potassium hydroxide) by the use of electrolysis of the molten salt with the newly invented [[voltaic pile]]. Previous attempts at electrolysis of the aqueous salt were unsuccessful due to potassium's extreme reactivity.<ref name="Greenwood&Earnshaw" />{{rp|68}} Potassium was the first metal that was isolated by electrolysis.<ref name=Enghag2004>{{cite book |last=Enghag|first=P.|year=2004|title=Encyclopedia of the elements|publisher=Wiley-VCH Weinheim|isbn=978-3-527-30666-4|chapter=11. Sodium and Potassium}}</ref> Later that same year, Davy reported extraction of sodium from the similar substance [[caustic soda]] (NaOH, lye) by a similar technique, demonstrating the elements, and thus the salts, to be different.<ref name="weeks" /><ref name="disco" /><ref name=Davy1807>{{cite journal |first=Humphry|last=Davy|title=On some new phenomena of chemical changes produced by electricity, in particular the decomposition of the fixed alkalies, and the exhibition of the new substances that constitute their bases; and on the general nature of alkaline bodies|pages=1–44|year=1808|volume=98|journal=Philosophical Transactions of the Royal Society of London|url=https://books.google.com/books?id=gpwEAAAAYAAJ&pg=PA57|doi=10.1098/rstl.1808.0001|doi-access=free}}</ref><ref name="200disco">{{cite journal |doi= 10.1134/S1061934807110160|title= History of the discovery of potassium and sodium (on the 200th anniversary of the discovery of potassium and sodium)|year= 2007|last1= Shaposhnik|first1= V. A.|journal= Journal of Analytical Chemistry|volume= 62|issue= 11|pages= 1100–1102|s2cid= 96141217}}</ref>

[[File:Johann Wolfgang Döbereiner.jpg|thumb|upright|[[Johann Wolfgang Döbereiner]] was among the first to notice similarities between what are now known as the alkali metals.]]
[[Petalite]] ({{chem2|LiAlSi4O10|auto=yes}}) was discovered in 1800 by the Brazilian chemist [[José Bonifácio de Andrada]] in a mine on the island of [[Utö, Sweden]].<ref name=mindat>{{cite web |url=http://www.mindat.org/min-3171.html |title=Petalite: Petalite mineral information and data |last1=Ralph |first1=Jolyon |last2=Chau |first2=Ida |date=24 August 2011 |access-date=27 November 2011 |archive-date=23 December 2017 |archive-url=https://web.archive.org/web/20171223062250/https://www.mindat.org/min-3171.html |url-status=live }}</ref><ref name=webelementshistory>{{cite web |url=http://www.webelements.com/lithium/history.html |title=WebElements Periodic Table of the Elements {{!}} Lithium {{!}} historical information |last=Winter |first=Mark |access-date=27 November 2011 |archive-date=16 October 2009 |archive-url=https://web.archive.org/web/20091016023617/http://www.webelements.com/lithium/history.html |url-status=live }}</ref><ref name=discovery>{{cite book |title=Discovery of the Elements |last=Weeks |first=Mary |year=2003 |page=124 |publisher=Kessinger Publishing |location=Whitefish, Montana, United States |isbn=978-0-7661-3872-8 }}</ref> However, it was not until 1817 that [[Johan August Arfwedson]], then working in the laboratory of the chemist [[Jöns Jacob Berzelius]], [[discovery of the chemical elements|detected]] the presence of a new element while analysing petalite [[ore]].<ref name=uwis>{{cite web |url=http://genchem.chem.wisc.edu/lab/PTL/PTL/BIOS/arfwdson.htm |archive-url=https://web.archive.org/web/20080605152857/http://genchem.chem.wisc.edu/lab/PTL/PTL/BIOS/arfwdson.htm |archive-date=5 June 2008 |title=Johan Arfwedson |access-date=10 August 2009}}</ref><ref name=vanderkrogt>{{cite web|publisher= Elementymology & Elements Multidict|title= Lithium|first= Peter|last= van der Krogt|url= http://elements.vanderkrogt.net/element.php?sym=Li|access-date= 5 October 2010|archive-date= 16 June 2011|archive-url= https://web.archive.org/web/20110616005621/http://elements.vanderkrogt.net/element.php?sym=li|url-status= live}}</ref> This new element was noted by him to form compounds similar to those of sodium and potassium, though its [[lithium carbonate|carbonate]] and [[lithium hydroxide|hydroxide]] were less [[solubility|soluble in water]] and more [[Base (chemistry)|alkaline]] than the other alkali metals.<ref name=compounds>{{cite web |url=http://www.chemguide.co.uk/inorganic/group1/compounds.html |title=Compounds of the Group 1 Elements |access-date=10 August 2009 |last=Clark |first=Jim |year=2005 |work=chemguide |archive-date=11 March 2009 |archive-url=https://web.archive.org/web/20090311150044/http://www.chemguide.co.uk/inorganic/group1/compounds.html |url-status=live }}</ref> Berzelius gave the unknown material the name ''lithion''/''lithina'', from the [[Ancient Greek|Greek]] word ''λιθoς'' (transliterated as ''lithos'', meaning "stone"), to reflect its discovery in a solid mineral, as opposed to potassium, which had been discovered in plant ashes, and sodium, which was known partly for its high abundance in animal blood. He named the metal inside the material ''lithium''.<ref name=krebs>{{cite book |last= Krebs|first= Robert E.|year= 2006|title= The History and Use of Our Earth's Chemical Elements: A Reference Guide|publisher= Greenwood Press|location= Westport, Conn.|isbn= 978-0-313-33438-2}}</ref><ref name=webelementshistory /><ref name=vanderkrogt /> Lithium, sodium, and potassium were part of the discovery of [[periodic table|periodicity]], as they are among a series of triads of elements in the same [[group (periodic table)|group]] that were noted by [[Johann Wolfgang Döbereiner]] in 1850 as having similar properties.<ref name="meta-synthesis2" />

[[File:Lepidolite-76774.jpg|thumb|upright|alt=A sample of lepidolite|[[Lepidolite]], the rubidium mineral from which rubidium was first isolated]]
Rubidium and caesium were the first elements to be discovered using the [[spectroscope]], invented in 1859 by [[Robert Bunsen]] and [[Gustav Kirchhoff]].<ref name="caesium">{{cite web|url=http://pubs.acs.org/cen/80th/print/cesium.html|title=C&EN: It's Elemental: The Periodic Table – Cesium|publisher=American Chemical Society|access-date=25 February 2010|last=Kaner|first=Richard|year=2003|archive-date=18 June 2015|archive-url=https://web.archive.org/web/20150618061523/http://pubs.acs.org/cen/80th/print/cesium.html|url-status=live}}</ref> The next year, they discovered caesium in the [[mineral water]] from [[Bad Dürkheim]], Germany. Their discovery of rubidium came the following year in [[Heidelberg]], Germany, finding it in the mineral [[lepidolite]].<ref name="BuKi1861">{{cite journal |title= Chemische Analyse durch Spectralbeobachtungen |pages= 337–381 |first1= G.|last1= Kirchhoff |first2= R.|last2= Bunsen|author-link1= Gustav Kirchhoff |author-link2 = Robert Bunsen|doi= 10.1002/andp.18611890702 |journal= Annalen der Physik und Chemie |volume= 189 |issue= 7|year= 1861 |bibcode=1861AnP...189..337K|hdl= 2027/uc1.$b278077 |url= http://archiv.ub.uni-heidelberg.de/volltextserver/15657/1/spektral.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://archiv.ub.uni-heidelberg.de/volltextserver/15657/1/spektral.pdf |archive-date=2022-10-09 |url-status=live }}</ref> The names of rubidium and caesium come from the most prominent lines in their [[emission spectra]]: a bright red line for rubidium (from the [[Latin]] word ''rubidus'', meaning dark red or bright red), and a sky-blue line for caesium (derived from the Latin word ''caesius'', meaning sky-blue).<ref name="Weeks">{{cite journal |title= The discovery of the elements. XIII. Some spectroscopic discoveries |pages= 1413–1434|last= Weeks|first= Mary Elvira |author-link=Mary Elvira Weeks|doi=10.1021/ed009p1413|journal= [[Journal of Chemical Education]] |volume= 9 |issue= 8 |year= 1932 |bibcode=1932JChEd...9.1413W}}</ref><ref>{{Cite OED|caesium|edition = 2nd}}</ref>

Around 1865 [[John Alexander Reina Newlands|John Newlands]] produced a series of papers where he listed the elements in order of increasing atomic weight and similar physical and chemical properties that recurred at intervals of eight; he likened such periodicity to the [[octave]]s of music, where notes an octave apart have similar musical functions.<ref>{{cite journal |title= On Relations Among the Equivalents |last=Newlands|first=John A. R. |journal= Chemical News |volume= 10 |pages= 94–95 |date= 20 August 1864 |url=http://web.lemoyne.edu/~GIUNTA/EA/NEWLANDSann.HTML |url-status=live |archive-url=https://web.archive.org/web/20110101073248/http://web.lemoyne.edu/~GIUNTA/EA/NEWLANDSann.HTML |archive-date=1 January 2011 |access-date=25 November 2013}}</ref><ref>{{cite journal |title= On the Law of Octaves |last=Newlands|first=John A. R. |journal= Chemical News |volume= 12 |page= 83 |date= 18 August 1865 |url=http://web.lemoyne.edu/~GIUNTA/EA/NEWLANDSann.HTML |url-status=live |archive-url=https://web.archive.org/web/20110101073248/http://web.lemoyne.edu/~GIUNTA/EA/NEWLANDSann.HTML |archive-date=1 January 2011 |access-date=25 November 2013}}</ref> His version put all the alkali metals then known (lithium to caesium), as well as copper, silver, and [[thallium]] (which show the +1 oxidation state characteristic of the alkali metals), together into a group. His table placed hydrogen with the [[halogen]]s.<ref name="meta-synthesis2" />

[[File:Mendelejevs periodiska system 1871.png|thumb|upright=1.75|[[Dmitri Mendeleev]]'s periodic system proposed in 1871 showing hydrogen and the alkali metals as part of his group I, along with copper, silver, and gold]]
After 1869, [[Dmitri Mendeleev]] proposed his periodic table placing lithium at the top of a group with sodium, potassium, rubidium, caesium, and thallium.<ref>{{cite journal |last=Mendelejew |first=Dimitri |year=1869 |title=Über die Beziehungen der Eigenschaften zu den Atomgewichten der Elemente |journal=Zeitschrift für Chemie |pages=405–406 |language=de}}</ref> Two years later, Mendeleev revised his table, placing hydrogen in group 1 above lithium, and also moving thallium to the [[boron group]]. In this 1871 version, copper, silver, and gold were placed twice, once as part of [[group 11 element|group IB]], and once as part of a "group VIII" encompassing today's groups [[group 8 element|8]] to 11.<ref name="Jensen">{{cite journal |last1=Jensen |first1=William B.|author1-link=William B. Jensen |year=2003 |title=The Place of Zinc, Cadmium, and Mercury in the Periodic Table |journal=Journal of Chemical Education |volume=80 |issue=8 |pages=952–961 |publisher=[[American Chemical Society]] |doi=10.1021/ed080p952 |bibcode=2003JChEd..80..952J |url=http://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/091.%20Zn-Cd-Hg.pdf |access-date=2012-05-06 |url-status=dead |archive-url=https://web.archive.org/web/20100611152417/http://www.che.uc.edu/jensen/W.%20B.%20Jensen/Reprints/091.%20Zn-Cd-Hg.pdf |archive-date=11 June 2010}}</ref><ref group="note">In the 1869 version of Mendeleev's periodic table, copper and silver were placed in their own group, aligned with hydrogen and [[mercury (element)|mercury]], while gold was tentatively placed under [[uranium]] and the undiscovered [[gallium|eka-aluminium]] in the [[boron group]].</ref> After the introduction of the 18-column table, the group IB elements were moved to their current position in the [[d-block]], while alkali metals were left in ''group IA''. Later the group's name was changed to ''group 1'' in 1988.<ref name = fluck/> The [[trivial name]] "alkali metals" comes from the fact that the hydroxides of the group 1 elements are all strong [[alkali]]s when dissolved in water.<ref name=rsc />

There were at least four erroneous and incomplete discoveries<ref name="fontani">{{cite conference |first= Marco |last= Fontani |title= The Twilight of the Naturally-Occurring Elements: Moldavium (Ml), Sequanium (Sq) and Dor (Do) |book-title= International Conference on the History of Chemistry |pages= 1–8 |date= 10 September 2005 |location= Lisbon|url= http://5ichc-portugal.ulusofona.pt/uploads/PaperLong-MarcoFontani.doc |archive-url= https://web.archive.org/web/20060224090117/http://5ichc-portugal.ulusofona.pt/uploads/PaperLong-MarcoFontani.doc |archive-date=24 February 2006|access-date= 8 April 2007}}</ref><ref name="vanderkrogt-Fr" /><ref>{{cite news |title= Education: Alabamine & Virginium|magazine=[[Time (magazine)|Time]] |date= 15 February 1932|url= http://www.time.com/time/magazine/article/0,9171,743159,00.html |archive-url= https://web.archive.org/web/20070930015028/http://www.time.com/time/magazine/article/0,9171,743159,00.html |url-status= dead |archive-date= 30 September 2007 |access-date= 1 April 2007|url-access=subscription }}</ref><ref>{{cite journal |last= MacPherson |first= H. G. |title= An Investigation of the Magneto-Optic Method of Chemical Analysis |journal= Physical Review |volume= 47 |issue= 4 |pages= 310–315 |publisher= American Physical Society|year=1934|doi= 10.1103/PhysRev.47.310|bibcode= 1935PhRv...47..310M}}</ref> before [[Marguerite Perey]] of the [[Curie Institute (Paris)|Curie Institute]] in Paris, France discovered francium in 1939 by purifying a sample of [[actinium-227]], which had been reported to have a decay energy of 220&nbsp;[[keV]]. However, Perey noticed decay particles with an energy level below 80&nbsp;keV. Perey thought this decay activity might have been caused by a previously unidentified decay product, one that was separated during purification, but emerged again out of the pure [[actinium]]-227. Various tests eliminated the possibility of the unknown element being [[thorium]], [[radium]], lead, [[bismuth]], or [[thallium]]. The new product exhibited chemical properties of an alkali metal (such as coprecipitating with caesium salts), which led Perey to believe that it was element 87, caused by the [[alpha decay]] of actinium-227.<ref name="chemeducator">Adloff, Jean-Pierre; Kaufman, George B. (25 September 2005). [http://chemeducator.org/sbibs/s0010005/spapers/1050387gk.htm Francium (Atomic Number 87), the Last Discovered Natural Element] {{webarchive |url=https://web.archive.org/web/20130604212956/http://chemeducator.org/sbibs/s0010005/spapers/1050387gk.htm |date=4 June 2013 }}. ''The Chemical Educator'' '''10''' (5). Retrieved 26 March 2007.</ref> Perey then attempted to determine the proportion of [[beta decay]] to alpha decay in actinium-227. Her first test put the alpha branching at 0.6%, a figure that she later revised to 1%.<ref name="mcgraw">{{cite book |contribution= Francium |year= 2002 |title= McGraw-Hill Encyclopedia of Science & Technology |volume= 7 |pages= [https://archive.org/details/mcgrawhillencycl165newy/page/493 493–494] |publisher= McGraw-Hill Professional |isbn= 978-0-07-913665-7 |title-link= McGraw-Hill Encyclopedia of Science & Technology }}</ref>
:{{nuclide|actinium|227}} {{overunderset|→|α (1.38%)|21.77 y}} '''{{nuclide|francium|223}}''' {{overunderset|→|β<sup>−</sup>|22 min}} {{nuclide|radium|223}} {{overunderset|→|α|11.4 d}}{{nuclide|radon|219}}

The next element below francium ([[Mendeleev's predicted elements|eka]]-francium) in the periodic table would be [[ununennium]] (Uue), element 119.<ref name="Uue" />{{rp|1729–1730}} The synthesis of ununennium was first attempted in 1985 by bombarding a target of [[einsteinium]]-254 with [[calcium]]-48 ions at the superHILAC accelerator at the [[Lawrence Berkeley National Laboratory]] in Berkeley, California. No atoms were identified, leading to a limiting yield of 300 [[barn (unit)|nb]].<ref name="link">{{cite journal |title=Search for superheavy elements using <sup>48</sup>Ca + <sup>254</sup>Es<sup>g</sup> reaction|first1=R. W. |last1=Lougheed|first2=J. H.|last2=Landrum|first3=E. K.|last3=Hulet|first4=J. F.|last4=Wild|first5=R. J.|last5=Dougan|first6=A. D.|last6=Dougan|first7=H.|last7=Gäggeler|first8=M.|last8=Schädel|first9=K. J.|last9=Moody|first10=K. E.|last10=Gregorich|last11=Seaborg|journal=Physical Review C|year=1985|pages=1760–1763|volume=32|issue=5|bibcode= 1985PhRvC..32.1760L|doi=10.1103/PhysRevC.32.1760|pmid=9953034 |first11=G.}}</ref><ref name="vanderkrogt-uue">{{cite web|publisher= Elementymology & Elements Multidict|title= Ununennium|first= Peter|last= van der Krogt|url= http://elements.vanderkrogt.net/element.php?sym=Uue|access-date= 14 February 2011|archive-date= 16 June 2011|archive-url= https://web.archive.org/web/20110616050413/http://elements.vanderkrogt.net/element.php?sym=Uue|url-status= live}}</ref>

:{{nuclide|einsteinium|254|link=y}} + {{nuclide|calcium|48|link=y}} → {{nuclide|ununennium|302}}* → ''no atoms''<ref group="note">The [[asterisk]] denotes an [[excited state]].</ref>

It is highly unlikely<ref name="link" /> that this reaction will be able to create any atoms of ununennium in the near future, given the extremely difficult task of making sufficient amounts of einsteinium-254, which is favoured for production of [[superheavy element|ultraheavy elements]] because of its large mass, relatively long half-life of 270 days, and availability in significant amounts of several micrograms,<ref>{{cite journal|last1=Schadel|first1=M.|last2=Brüchle|first2=W.|last3=Brügger|first3=M.|last4=Gäggeler|first4=H.|last5=Moody|first5=K.|last6=Schardt|first6=D.|last7=Sümmerer|first7=K.|last8=Hulet|first8=E.|last9=Dougan|first9=A.|last10=Dougan|title=Heavy isotope production by multinucleon transfer reactions with <sup>254</sup>Es|journal=Journal of the Less Common Metals|volume=122|pages=411–417|year=1986|doi=10.1016/0022-5088(86)90435-2|first10=R. J.|last11=Landrum|first11=J. H.|last12=Lougheed|first12=R. W.|last13=Wild|first13=J. F.|last14=O'Kelley|first14=G. D.|last15=Hahn|first15=R. L.|display-authors=9|url=https://zenodo.org/record/1253958|archive-date=25 November 2020|access-date=28 June 2019|archive-url=https://web.archive.org/web/20201125002148/https://zenodo.org/record/1253958|url-status=live}}</ref> to make a large enough target to increase the sensitivity of the experiment to the required level; einsteinium has not been found in nature and has only been produced in laboratories, and in quantities smaller than those needed for effective synthesis of superheavy elements. However, given that ununennium is only the first [[period 8 element]] on the [[extended periodic table]], it may well be discovered in the near future through other reactions, and indeed an attempt to synthesise it is currently ongoing in Japan.<ref name=Enyo>{{Cite news|url=https://www.chemistryworld.com/news/hunt-for-element-119-to-begin-this-year/3007977.article|title=Hunt for element 119 set to begin|newspaper=Chemistry World|date=12 September 2017|access-date=9 January 2018|archive-date=11 November 2020|archive-url=https://web.archive.org/web/20201111184337/https://www.chemistryworld.com/news/hunt-for-element-119-to-begin-this-year/3007977.article|url-status=live}}</ref> Currently, none of the period 8 elements has been discovered yet, and it is also possible, due to [[nucleon drip line|drip instabilities]], that only the lower period 8 elements, up to around element 128, are physically possible.<ref name=EB>{{cite encyclopedia|last=Seaborg|first=G. T.|url=https://www.britannica.com/EBchecked/topic/603220/transuranium-element|title=transuranium element (chemical element)|encyclopedia=Encyclopædia Britannica|date=c. 2006|access-date=16 March 2010|archive-date=30 November 2010|archive-url=https://web.archive.org/web/20101130112151/https://www.britannica.com/EBchecked/topic/603220/transuranium-element|url-status=live}}</ref><ref name="emsley">{{cite book |last=Emsley|first=John|title=Nature's Building Blocks: An A-Z Guide to the Elements|edition=New|year=2011|publisher=Oxford University Press|location=New York, NY|isbn=978-0-19-960563-7|page=593}}</ref> No attempts at synthesis have been made for any heavier alkali metals: due to their extremely high atomic number, they would require new, more powerful methods and technology to make.<ref name="Uue" />{{rp|1737–1739}}