From today's featured article![]() Periodic-table cell for hassium Hassium is a highly radioactive chemical element with symbol Hs and atomic number 108. The most stable known isotopes have half-lives of around 10 seconds. Natural occurrences of this superheavy element have been hypothesised, but none has ever been found. The first attempts to artificially prepare element 108 by nuclear fusion began in 1978 at the Joint Institute for Nuclear Research in the Soviet Union; though likely successful by 1984, these experiments did not prove conclusively that the element had been synthesised. For this reason, the discovery is principally credited to a team led by Peter Armbruster and Gottfried Münzenberg at the Gesellschaft für Schwerionenforschung who bombarded lead-208 with iron-58 and produced hassium-265. The name hassium was selected as a reference to the German state of Hesse, where the research was conducted. The observed chemical properties of hassium are consistent with its expected placement as the group 8 element in period 7 of the periodic table. (Full article...)
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The U.S. state of Washington has thirty-nine counties. The Provisional Government of Oregon established Vancouver and Lewis Counties in 1845 in unorganized Oregon Country, extending from the Columbia River north to 54°40′ north latitude. After the region was organized within the Oregon Territory with the current northern border of 49° north, Vancouver County was renamed Clarke, and six more counties were created out of Lewis County before the organization of Washington Territory in 1853; twenty-eight were formed during Washington's territorial period, two of which only existed briefly. The final five were established in the 22 years after Washington was admitted to the Union as the 42nd state in 1889. King County, home to the state's largest city, Seattle, holds 30 percent of Washington's population (2,252,782 residents of 7,614,893 in 2019), and has the highest population density, with more than 1,000 people per square mile (400/km2). Garfield County is both the least populated (2,225) and least densely populated (3.1/sq mi [1.2/km2]). (Full list...)
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Pierre Gaveaux (9 October 1761 – 5 February 1825) was a French operatic tenor and composer. He is notable for creating the role of Jason in Cherubini's Médée and for composing Léonore; ou, L'amour conjugal, the first operatic version of the story that later found fame as Beethoven's Fidelio. Early in his career, he was a conductor at the Grand Théâtre de Bordeaux, but later moved to Paris, taking on various operatic roles and composing several operas that were performed throughout Europe. During the French Revolution, he composed a hymn to the Supreme Being. This illustration of Gaveaux by Edmé Quenedey was produced through the use of a physiognotrace, an instrument designed to trace a person's physiognomy and make semi-automated portrait aquatints. Illustration credit: Edmé Quenedey des Ricets; restored by Adam Cuerden
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