Editing Technetium (section)

===Official discovery and later history===
The [[Discovery of the chemical elements|discovery]] of element&nbsp;43 was finally confirmed in a 1937 experiment at the [[University of Palermo]] in Sicily by [[Carlo Perrier]] and [[Emilio Segrè]].<ref>{{cite book |last=Heiserman |first=D. L. |year=1992 |chapter=Element&nbsp;43: Technetium |title=Exploring Chemical Elements and their Compounds |location=New York, NY |publisher=TAB Books |isbn=978-0-8306-3018-9 |chapter-url=https://archive.org/details/exploringchemica01heis |page=164}}</ref> In mid-1936, Segrè visited the United States, first [[Columbia University]] in New York and then the [[Lawrence Berkeley National Laboratory]] in California. He persuaded [[cyclotron]] inventor [[Ernest Lawrence]] to let him take back some discarded cyclotron parts that had become [[radioactive]]. Lawrence mailed him a [[molybdenum]] foil that had been part of the deflector in the cyclotron.<ref>{{cite book |first=Emilio |last=Segrè |date=1993 |title=A Mind Always in Motion: The autobiography of Emilio Segrè |publisher=University of California Press |location=Berkeley, CA |isbn=978-0520076273 |pages=[https://archive.org/details/mindalwaysinmoti00segr/page/115 115–118] |url=https://archive.org/details/mindalwaysinmoti00segr/page/115 }}</ref>

Segrè enlisted his colleague Perrier to attempt to prove, through comparative chemistry, that the molybdenum activity was indeed from an element with the atomic number 43. In 1937, they succeeded in isolating the [[isotope]]s [[technetium-95]]m and [[technetium-97]].<ref name=segre/><ref name=blocks>{{harvnb|Emsley|2001|pp=[https://archive.org/details/naturesbuildingb0000emsl/page/422 422]–425}}</ref>{{Disputed inline|First isotopes known|date=April 2024}} [[University of Palermo]] officials wanted them to name their discovery {{lang|la|panormium}}, after the Latin name for [[Palermo]], ''{{lang|la|Panormus}}''. In 1947,<ref name=segre>{{cite journal |last1= Perrier |first1= C. |last2= Segrè |first2= E. |date= 1947 |title=Technetium: The element of atomic number&nbsp;43 |journal= Nature |volume= 159 |issue= 4027 |page= 24 |doi= 10.1038/159024a0 |pmid= 20279068 |bibcode= 1947Natur.159...24P |s2cid= 4136886}}</ref> element 43 was named after the [[Greek language|Greek]] word {{Transliteration|el|technetos}} ({{lang|el|τεχνητός}}), meaning 'artificial', since it was the first element to be artificially produced.<ref name=history-origin/><ref name=multidict>
{{cite web
 |last=van der Krogt |first=P.
 |series=Elentymolgy and Elements Multidict
 |title=Technetium
 |url=http://elements.vanderkrogt.net/element.php?sym=Tc
 |access-date=2009-05-05
}}
</ref>
Segrè returned to Berkeley and met [[Glenn T. Seaborg]]. They isolated the [[metastable isotope]] [[technetium-99m]], which is now used in some ten million medical diagnostic procedures annually.<ref>
{{cite book
 |last1=Hoffman |first1=Darleane C.
 |last2=Ghiorso |first2=Albert
 |last3=Seaborg |first3=Glenn T.
 |date =2000
 |chapter=Chapter&nbsp;1.2: Early days at the Berkeley Radiation Laboratory
 |title=The Transuranium People: The inside story
 |series = [[Lawrence Berkeley National Laboratory]]
 |publisher = University of California Press
 |place = Berkeley, CA
 |isbn=978-1-86094-087-3
 |page =15
 |chapter-url =http://www.worldscibooks.com/physics/p074.html
 |access-date = 2007-03-31 |url-status=dead
 |archive-url =https://web.archive.org/web/20070124220556/http://www.worldscibooks.com/physics/p074.html
 |archive-date=2007-01-24
}}
</ref>

In 1952, the astronomer [[Paul W. Merrill]] detected the [[emission spectrum|spectral signature]] of technetium (specifically [[wavelength]]s of 403.1&nbsp;[[Nanometre|nm]], 423.8&nbsp;nm, 426.2&nbsp;nm, and 429.7&nbsp;nm) in light from [[Stellar classification#Class S|S-type]] [[red giant]]s.<ref>{{cite journal |last=Merrill |first=P.W. |date=1952 |title=Technetium in the stars |journal=Science |volume=115 |issue=2992|pages=479–489, esp.&nbsp;484 |doi=10.1126/science.115.2992.479|pmid=17792758 |bibcode=1952Sci...115..479. }}</ref> The stars were near the end of their lives but were rich in the short-lived element, which indicated that it was being produced in the stars by [[nuclear reaction]]s. That evidence bolstered the hypothesis that heavier elements are the product of [[nucleosynthesis]] in stars.<ref name=blocks/> More recently, such observations provided evidence that elements are formed by [[neutron capture]] in the [[s-process]].<ref name=s8>{{harvnb|Schwochau|2000|pp=7–9}}</ref>

Since that discovery, there have been many searches in terrestrial materials for natural sources of technetium. In 1962, technetium-99 was isolated and identified in [[uraninite|pitchblende]] from the [[Belgian Congo]] in very small quantities (about 0.2&nbsp;ng/kg),<ref name=s8/> where it originates as a [[spontaneous fission]] product of [[uranium-238]]. The [[natural nuclear fission reactor]] in [[Oklo]] contains evidence that significant amounts of technetium-99 were produced and have since decayed into [[ruthenium-99]].<ref name=s8/>