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Lanthanide metals react exothermically with hydrogen to form LnH 2, dihydrides. [1] With the exception of Eu and Yb, which resemble the Ba and Ca hydrides (non-conducting, transparent salt-like compounds),they form black pyrophoric, conducting compounds [6] where the metal sub-lattice is face centred cubic and the H atoms occupy tetrahedral sites. [1]
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals.
Dysprosium is a chemical element; it has symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime.
Lanthanide chlorides are a group of chemical compounds that can form between a lanthanide element (from lanthanum to lutetium) and chlorine.The lanthanides in these compounds are usually in the +2 and +3 oxidation states, although compounds with lanthanides in lower oxidation states exist.
Lanthanum hydroxide can be obtained by adding an alkali such as ammonia to aqueous solutions of lanthanum salts such as lanthanum nitrate. This produces a gel-like precipitate that can then be dried in air. [2] La(NO 3) 3 + 3 NH 4 OH → La(OH) 3 + 3 NH 4 NO 3. Alternatively, it can be produced by hydration reaction (addition of water) to ...
The medicinal uses of insects and other arthropods worldwide have been reviewed by Meyer-Rochow, [1] who provides examples of all major insect groups, spiders, worms and molluscs and discusses their potential as suppliers of bioactive components. Using insects (and spiders) to treat various maladies and injuries has a long tradition and, having ...
Human interactions with fungi include both beneficial uses, whether practical or symbolic, and harmful interactions such as when fungi damage crops, timber, food, or are pathogenic to animals. Yeasts have been used since ancient times to leaven bread and to ferment beer and wine .
The Occupational Safety and Health Administration (OSHA) has set the legal limit (Permissible exposure limit) for fluorine exposure in the workplace as 0.1 ppm (0.2 mg/m 3) over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 0.1 ppm (0.2 mg/m 3) over an 8-hour ...