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cerium

(Encyclopedia)cerium sērˈēəm [key] [from the asteroid Ceres], metallic chemical element; symbol Ce; at. no. 58; at. wt. 140.116; m.p. 799℃; b.p. 3,426℃; sp. gr. 6.77 at 25℃; valence +3 or +4. Cerium is a ...

concretion

(Encyclopedia)concretion, mass or nodule of mineral matter, usually oval or nearly spherical in shape, and occurring in sedimentary rock. It is formed by the accumulation of mineral matter in the pore spaces of the...

astringent

(Encyclopedia)astringent əstrĭnˈjənt [key], substance that shrinks body tissues. Astringent medicines cause shrinkage of mucous membranes or exposed tissues and are often used internally to check discharge of s...

limonite

(Encyclopedia)limonite hĕmˈətīt, hēˈ– [key], yellowish to dark brown mineral, a hydrated oxide of iron, FeO(OH)·nH2O, occurring commonly in deposits of secondary origin, i.e., those formed by the alteratio...

copper, chemical element

(Encyclopedia)copper, metallic chemical element; symbol Cu [Lat. cuprum=copper]; at. no. 29; at. wt. 63.546; m.p. 1,083.4℃; b.p. 2,567℃; sp. gr. 8.96 at 20℃; valence +1 or +2. Copper and some of its alloys ha...

chromite

(Encyclopedia)chromite krōˈmīt [key], dark brown to black mineral. It is an iron-chromium oxide, FeCr2O4, with traces of magnesium and aluminum. Its crystals are octahedral, but rare; it usually occurs as irregu...

germanium

(Encyclopedia)germanium jərmāˈnēəm [key] [from Germany], semimetallic chemical element; symbol Ge; at. no. 32; at. wt. 72.63; m.p. 937.4℃; b.p. 2,830℃; sp. gr. 5.323 at 25℃; valence +2 or +4. Pure german...

iron

(Encyclopedia)iron, metallic chemical element; symbol Fe [Lat. ferrum]; at. no. 26; at. wt. 55.845; m.p. about 1,535℃; b.p. about 2,750℃; sp. gr. 7.87 at 20℃; valence +2, +3, +4, or +6. Iron is biologically s...

Benedict's solution

(Encyclopedia)Benedict's solution, deep-blue alkaline solution used to test for the presence of the aldehyde functional group, −CHO. The substance to be tested is heated with Benedict's solution; formation of a b...

Yoshino, Akira

(Encyclopedia)Yoshino, Akira, 1948–, Japanese chemist, Ph.D. Osaka Univ., 2005. He was a researcher at Asahi Kasei Corp. from 1972 to 2017, when he became a professor at Meijo Univ., Nagoya, Japan. Akira received...