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Author: langbot
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English[en]
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It seldom occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium – from Greek selḗnē (σελήνη 'Moon') – was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of DC power surge protectors and one type of fluorescent quantum dot.
Cornish[kw]
Elven gymyk yw seleniom, niver 34 y'n Vosen Beriodek. Y furvell gymyk yw Se. An hanow a dheu dhyworth an ger selene, hanow Greka dhe'n Loor. Elven essensek dhe'n korf denel yw seleniom. Rann yw dhe'n ensaymow glutathion peroksidas ha deyodinas. Yn despit dhe hemma seleniom a yll bos gwenonek (a ugh 450μg an jydh). Arwodhow a bosna seleniom yw anal flerys. Seleniom a yll defolya. Yn 1983 defolyes veu kreun dowr Kesterson yn nans San Joaquin, Kaliforni, gans seleniom dhyworth bargennyow tir leel. Diskudhys veu seleniom gans Jöns Jacob Berzelius (1779-1848) yn Stockholm yn 1817. Ev a wrug hwithrans war remenant orth goles kerynyow yn gweythva trenken sulfur. Ev a verkyas bos seleniom hevelep dhe deloriom. Hemma veu an acheson rag an hanow (seleniom - an Loor, ha teloriom - an Norvys). Tanow yw monow seleniom. Askorrys yw avel isaskorr purhe kober, plomm ha zynk, dell yw usys. An askorroryon moyha yw Kanada, an Statys Unys, Bolivi ha Russi, a-dro dhe 1500 tonnas an vledhen (hag eylgylghys yw 150 tonnas aral). Alkan seleniom a wra kendegi milgweyth gwell pan vo y'n howlsplann. Usys yw ytho rag kellow fototredanek, liesskrifellow ha panellow howlek (30% a askorrans). Usys yw 25% dhe wul gweder (keworrys selenat sodiom (Na2SeO4) dh'y dhasliwa, po selenid kadmiom dhe wul gweder rudhem), yn arbennek gweder liw brons rag tourow ebron. Usys yw 15% avel selenat sodiom dhe wul boos enevales. Keworrys yw kesstoffow seleniom dhe shampoo gorth-lownyow kroghen an penn. Poos atomek seleniom yw 78.96, y boynt teudhi yw 217°C ha'y boynt bryjyon yw 685°C. Y dhosedh yw 4.8kg an liter. Seleniom a eksist avel diw furv: alkan arghansek po polter rudh.