Editing Group 9 element (section)

===Iridium===
Chemists who studied platinum dissolved it in [[aqua regia]] (a mixture of [[hydrochloric acid|hydrochloric]] and [[nitric acid]]s) to create soluble salts. They always observed a small amount of a dark, insoluble residue.<ref name="hunt">{{cite journal |title=A History of Iridium |first=L. B. |last=Hunt |journal=Platinum Metals Review |volume=31 |issue=1 |date=1987 |pages=32–41 |doi=10.1595/003214087X3113241 |url=https://technology.matthey.com/documents/496120/626258/pmr-v31-i1-032-041.pdf/ |access-date=2023-10-12 |archive-date=2022-09-29 |archive-url=https://web.archive.org/web/20220929092320/https://technology.matthey.com/documents/496120/626258/pmr-v31-i1-032-041.pdf/ |url-status=dead |url-access=subscription }}</ref> In 1803, British scientist [[Smithson Tennant]] (1761–1815) analyzed the insoluble residue and concluded that it must contain a new metal. Vauquelin treated the powder alternately with alkali and acids<ref name="Emsley">{{cite book| title=Nature's Building Blocks: An A–Z Guide to the Elements| last=Emsley| first=J.| publisher=[[Oxford University Press]]| date=2003| location=Oxford, England, UK| isbn=978-0-19-850340-8| chapter=Iridium| pages=[https://archive.org/details/naturesbuildingb0000emsl/page/201 201–204]| chapter-url=https://archive.org/details/naturesbuildingb0000emsl/page/201}}</ref> and obtained a volatile new oxide, which he believed to be of this new metal—which he named ''ptene'', from the Greek word {{lang|el|πτηνός}} ''ptēnós'', "winged".<ref>{{cite book |title=A System of Chemistry of Inorganic Bodies |url=https://archive.org/details/asystemchemistr07thomgoog |author=Thomson, T. |author-link=Thomas Thomson (chemist) |publisher=Baldwin & Cradock, London; and William Blackwood, Edinburgh |date=1831 |volume=1 |page=[https://archive.org/details/in.ernet.dli.2015.32266/page/n721/mode/2up 693]}}</ref><ref name="griffith" /> Tennant, who had the advantage of a much greater amount of residue, continued his research and identified the two previously undiscovered elements in the black residue, iridium and osmium.<ref name="hunt" /><ref name="Emsley" /> He obtained dark red crystals (probably of {{chem|Na|2|[IrCl|6}}]·''n''{{chem|H|2|O}}) by a sequence of reactions with [[sodium hydroxide]] and [[hydrochloric acid]].<ref name="griffith" /> He named iridium after [[Iris (mythology)|Iris]] ({{lang|el|Ἶρις}}), the Greek winged goddess of the rainbow and the messenger of the Olympian gods, because many of the [[Salt (chemistry)|salts]] he obtained were strongly colored.{{efn|''Iridium'' literally means "of rainbows".}}<ref>{{cite book |title=Discovery of the Elements |url=https://archive.org/details/discoveryofeleme0000week |url-access=registration |pages=[https://archive.org/details/discoveryofeleme0000week/page/414 414–418] |author=Weeks, M. E. |date=1968 |edition=7th |publisher=Journal of Chemical Education |isbn=978-0-8486-8579-9 |oclc=23991202}}</ref> Discovery of the new elements was documented in a letter to the [[Royal Society]] on June 21, 1804.<ref name="hunt"/><ref>{{cite journal |title=On Two Metals, Found in the Black Powder Remaining after the Solution of Platina |first=S. |last=Tennant |journal=Philosophical Transactions of the Royal Society of London |volume=94 |date=1804 |pages=411–418 |jstor=107152 |doi=10.1098/rstl.1804.0018 |url=https://zenodo.org/record/1432312 |doi-access=}}</ref>