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Metallic scandium was produced for the first time in 1937 by electrolysis of a eutectic mixture, at 700–800 °C, of potassium, lithium, and scandium chlorides. [33] Scandium exists in the same ores that yttrium had been discovered from, but is much rarer and probably for that reason had eluded discovery. [25]
To produce metallic scandium, the oxide is converted to scandium fluoride and then reduced with metallic calcium. [32] Sc 2 O 3 + 6HF → 2ScF 3 + 3H 2 O; 2ScF 3 + 3Ca → 3CaF 2 + 2Sc; Madagascar and the Iveland-Evje region in Norway have the only deposits of minerals with high scandium content, thortveitite (Sc,Y) 2 (Si 2 O 7), but these are ...
Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". [8] Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free ...
An open circuit SCBA typically has three main components: a high-pressure gas storage cylinder, (e.g., 2,216 to 5,500 psi (15,280 to 37,920 kPa), about 150 to 374 atmospheres), a pressure regulator, and a respiratory interface, which may be a mouthpiece, half mask or full-face mask, assembled and mounted on a framed carrying harness. [2]
The chemistry of scandium is almost completely dominated by the trivalent ion, Sc 3+, due to its electron configuration, [Ar] 3d 1 4s 2. The radii of M 3+ ions in the table below indicate that the chemical properties of scandium ions have more in common with yttrium ions than with aluminium ions. In part because of this similarity, scandium is ...
A World War I British P Helmet, c. 1915 Zelinsky–Kummant protivogaz, designed in 1915, was one of the first modern-type full-head protection gas masks with a detachable filter and eyelet glasses, shown here worn by U.S. Army soldier (USAWC photo) Indian muleteers and mule wearing gas masks, France, February 21, 1940 A Polish SzM-41M KF gas mask, used from the 1950s through to the 1980s
Earlier versions of the gas mask prior to 1915s development of the small box respirator were crude and ineffective as no troops had yet experienced poison warfare. One of the first gas masks seen in the early part of the war was the British hypo helmet, after recent failure and ineffectiveness of the black veil respirator. The helmet was ...
Organoscandium chemistry is an area with organometallic compounds focused on compounds with at least one carbon to scandium chemical bond. [ 2 ] [ 3 ] The interest in organoscandium compounds is mostly academic but motivated by potential practical applications in catalysis , especially in polymerization .
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