Editing Holmium (section)

==History==

Holmium ({{lang|la|Holmia}}, [[Latin]] name for [[Stockholm]]) was [[discovery of the chemical elements|discovered]] by the Swiss chemists [[Jacques-Louis Soret]] and [[Marc Delafontaine]] in 1878 who noticed the aberrant [[Spectrophotometry|spectrographic]] [[emission spectrum]] of the then-unknown element (they called it "Element X").<ref>{{cite journal|title = Sur les spectres d'absorption ultra-violets des terres de la gadolinite|author = Jacques-Louis Soret|journal = Comptes rendus de l'Académie des sciences|volume = 87|pages = 1062|date = 1878|url = http://gallica.bnf.fr/ark:/12148/bpt6k3043m/f1124.table}}
</ref><ref>{{cite journal|title = Sur le spectre des terres faisant partie du groupe de l'yttria
|author = Jacques-Louis Soret|journal = Comptes rendus de l'Académie des sciences
|volume = 89|pages = 521|date = 1879|url = https://gallica.bnf.fr/ark:/12148/bpt6k3046j/f550.table}}
</ref>

The Swedish chemist [[Per Teodor Cleve]] also independently discovered the element while he was working on [[erbia]] earth ([[erbium oxide]]). He was the first to isolate impure oxide of the new element.<ref name="RSHolmium">{{cite web |title=Holmium |url=https://www.rsc.org/periodic-table/element/67/holmium |website=Royal Society of Chemistry|date= 2020 |access-date=4 January 2020}}</ref><ref name="Virginia">{{cite journal |last1=Marshall |first1=James L. Marshall |last2=Marshall |first2=Virginia R. Marshall |title=Rediscovery of the elements: The Rare Earths–The Confusing Years |journal=The Hexagon |date=2015 |pages=72–77 |url=http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/rare%20earths%20II.pdf |access-date=30 December 2019}}</ref><ref name="Weeks">{{cite book |last1=Weeks |first1=Mary Elvira |title=The discovery of the elements |date=1956 |publisher=Journal of Chemical Education |page=710}}</ref> Using the method developed by the Swedish chemist [[Carl Gustaf Mosander]], Cleve first removed all of the known contaminants from erbia. The result of that effort was two new materials, one brown and one green. He named the brown substance ''holmia'' (after the Latin name for Cleve's home town, Stockholm) and the green one ''thulia''. ''Holmia'' was later found to be the [[holmium oxide]], and ''thulia'' was [[thulium oxide]].<ref name="emsley225" /> The pure oxide was only isolated in 1911 and the metal in 1939 by Heinrich Bommer.<ref name="Sicius-2024">{{Cite book |last=Sicius |first=Hermann |url=https://link.springer.com/10.1007/978-3-662-68921-9 |title=Handbook of the Chemical Elements |date=2024 |publisher=Springer Berlin Heidelberg |isbn=978-3-662-68920-2 |location=Berlin, Heidelberg |language=en |doi=10.1007/978-3-662-68921-9}}</ref>{{rp|959}}<ref>{{Cite journal|last=Bommer |first=Heinrich |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/zaac.19392420307 |journal=Zeitschrift für anorganische und allgemeine Chemie|volume=242|issue=3|title=Kristallstruktur und magnetisches Verhalten des metallischen Holmiums |date=1939 |pages=277–280 |language=de |doi=10.1002/zaac.19392420307}}</ref>

In the English physicist [[Henry Moseley]]'s classic paper on [[atomic number]]s, holmium was assigned the value 66. The holmium preparation he had been given to investigate had been impure, dominated by neighboring dysprosium. He would have seen [[X-ray emission spectroscopy|x-ray emission lines]] for both elements, but assumed that the dominant ones belonged to holmium, instead of the dysprosium impurity.<ref>{{cite journal|last1=Egdell|first1=Russell G.|last2=Bruton|first2=Elizabeth|date=2020|title=Henry Moseley, X-ray spectroscopy and the periodic table|journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences|volume=378|issue=2180|doi=10.1002/chem.202004775|pmid=32811359|doi-access=free}}</ref>