Editing Uranium (section)

===Discovery===
[[File:Uranus_Voyager2_color_calibrated.png|thumb|left|upright|The planet [[Uranus]], which uranium is named after]]
The [[discovery of the chemical elements|discovery]] of the element is credited to the German chemist [[Martin Heinrich Klaproth]]. While he was working in his experimental laboratory in [[Berlin]] in 1789, Klaproth was able to precipitate a yellow compound (likely [[sodium diuranate]]) by dissolving [[pitchblende]] in [[nitric acid]] and neutralizing the solution with [[sodium hydroxide]].{{sfn|Emsley|2001|p=477}} Klaproth assumed the yellow substance was the oxide of a yet-undiscovered element and heated it with [[charcoal]] to obtain a black powder, which he thought was the newly discovered metal itself (in fact, that powder was an [[oxide of uranium]]).{{sfn|Emsley|2001|p=477}}<ref>{{cite journal
| title = Chemische Untersuchung des Uranits, einer neuentdeckten metallischen Substanz
| author = Klaproth, M. H.
| journal = Chemische Annalen
| volume = 2
| date = 1789
| pages = 387–403
| author-link = Martin Heinrich Klaproth}}</ref> He named the newly discovered element after the planet [[Uranus]] (named after the primordial [[Uranus (mythology)|Greek god of the sky]]), which had been discovered eight years earlier by [[William Herschel]].<ref>{{cite encyclopedia|edition=4th|title=Uranium|encyclopedia=The American Heritage Dictionary of the English Language |publisher=Houghton Mifflin Company|url=http://www.answers.com/uranium|access-date=15 January 2007|archive-date=27 July 2011 |archive-url=https://web.archive.org/web/20110727194715/http://www.answers.com/uranium|url-status=dead}}</ref>

In 1841, [[Eugène-Melchior Péligot]], Professor of Analytical Chemistry at the [[Conservatoire National des Arts et Métiers]] (Central School of Arts and Manufactures) in [[Paris]], isolated the first sample of uranium metal by heating [[uranium tetrachloride]] with [[potassium]].{{sfn|Emsley|2001|p=477}}<ref>{{cite journal| title=Recherches Sur L'Uranium
| author=Péligot, E.-M. |journal=[[Annales de chimie et de physique]]
| volume=5 |issue=5 |date=1842
| pages=5–47 |url=http://gallica.bnf.fr/ark:/12148/bpt6k34746s/f4.table}}</ref>

[[File:Becquerel plate.jpg|thumb|[[Henri Becquerel]] discovered [[radioactivity]] by exposing a [[photographic plate]] to uranium in 1896.|alt=Two fuzzy black features on a fuzzy white paper-like background. There is a handwriting at the top of the picture.]]
[[Henri Becquerel]] discovered radioactivity by using uranium in 1896.<ref name="ColumbiaEncy" /> Becquerel made the discovery in Paris by leaving a sample of a uranium salt, K{{sub|2}}UO{{sub|2}}(SO{{sub|4}}){{sub|2}} (potassium uranyl sulfate), on top of an unexposed [[photographic plate]] in a drawer and noting that the plate had become "fogged".{{sfn|Emsley|2001|p=478}} He determined that a form of invisible light or rays emitted by uranium had exposed the plate.

During World War I when the [[Central Powers]] suffered a shortage of molybdenum to make artillery gun barrels and high speed tool steels, they routinely used [[ferrouranium]] alloy as a substitute, as it presents many of the same physical characteristics as molybdenum. When this practice became known in 1916 the US government requested several prominent universities to research the use of uranium in manufacturing and metalwork. Tools made with these formulas remained in use for several decades,<ref>{{cite web|url=https://books.google.com/books?id=-5c7AQAAMAAJ&q=ferrouranium+artillery&pg=PA367|title=The Electric Journal|date=10 April 1920|publisher=Westinghouse Club |via=Google Books}}</ref><ref>{{cite book |url=https://books.google.com/books?id=kfvBmuFOAiEC&pg=PA8 |title=Preparation of ferro-uranium |first1=Horace Wadsworth |last1=Gillett |first2=Edward Lawrence |last2=Mack |date=10 April 1917 |series=Technical Paper 177 – U.S. Bureau of Mines |publisher=U.S. Govt. print. off. |via=Google Books}}</ref> until the [[Manhattan Project]] and the [[Cold War]] placed a large demand on uranium for fission research and weapon development.