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31. GalliumName: Gallium
It is the only metal, except for mercury, caesium, and rubidium, which can be liquid near room temperatures; this makes possible its use in high-temperature thermometers. It has one of the longest liquid ranges of any metal and has a low vapour pressure even at high temperatures. Ultra-pure gallium has a beautiful, silvery appearance, and the solid metal exhibits a conchoidal fracture similar to glass. The metal expands on solidifying; therefore, it should not be stored in glass or metal containers, as they may break as the metal solidifies. High-purity gallium is attacked only slowly by mineral acids. Gallium arsenide is capable of converting electricity directly into coherent light and gallium arsenide is a key component of LEDs (light emitting diodes). Gallium (Latin Gallia meaning "France"; also gallus, meaning "cock") was discovered spectroscopically by Lecoq de Boisbaudran in 1875 by its characteristic spectrum (two violet lines) in an examination of a zinc blend from the Pyrenees. Before its discovery, most of its properties had been predicted and described by Dmitri Mendeleev (who called the hypothetical element eka-aluminium) on the basis of its position in his periodic table. Later in 1875, Bo isbaudran obtained the free metal through the electrolysis of its hydroxide in KOH solution. He named the element after his native land of France and, in one of those multilingual puns so beloved of men of science of the early 19th century, after himself, as 'Lecoq' = the rooster, and Latin for rooster is "gallus". While not considered toxic, the data about gallium is inconclusive. Some sources suggest that it may cause dermatitis from prolonged exposure, other tests have not caused a positive reaction. Quick links
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