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Graham, Thomas

(Encyclopedia)Graham, Thomas, 1805–69, Scottish chemist, best known for research in diffusion in both gases and liquids that led to his formulation of Graham's law. His discovery that certain substances (e.g., gl...

ammonium chloride

(Encyclopedia)ammonium chloride əmōˈnēəm klôrˈīd [key], chemical compound, NH4Cl, a white or colorless, odorless, water-soluble, cubic crystalline salt with a biting taste, commonly known as sal ammoniac. I...

indicators, acid-base

(Encyclopedia)indicators, acid-base, organic compounds that, in aqueous solution, exhibit color changes indicative of the acidity or basicity of the solution. Common indicators include p-nitrophenol, which is color...

Dale, Sir Henry Hallett

(Encyclopedia)Dale, Sir Henry Hallett, 1875–1968, English scientist. For his study of acetylcholine as agent in the chemical transmission of nerve impulses he shared with Otto Loewi the 1936 Nobel Prize in Physio...

Cherkasy

(Encyclopedia)Cherkasy chĭrkäˈsē [key], city (1989 pop. 290,000), capital of Cherkasy region, in central Ukraine, a port on the Dnieper River. Situated on the shore of the Kremenchuk Reservoir, Cherkasy has foo...

Rock Springs

(Encyclopedia)Rock Springs, city (1990 pop. 19,050), alt. c.6,270 ft (1,910 m), Sweetwater co., SW Wyo., on Bitter Creek; inc. 1888. It is a cattle and sheep shipping point and the center of large natural trona min...

silica gel

(Encyclopedia)silica gel, chemical compound. It is a colloidal form of silica, and usually resembles coarse white sand. It may be prepared by partial dehydration of metasilicic acid, H2SiO3. Because it has many tin...

sodium thiosulfate

(Encyclopedia)sodium thiosulfate, Na2S2O3, colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3·5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite o...

Zabrze

(Encyclopedia)Zabrze zäbˈzhĕ [key], Ger. Hindenburg, city (1992 est. pop. 202,800), Śląskie prov., S Poland. It is a railway junction in the Katowice mining and industrial region. Local coal deposits form the ...

Krebs cycle

(Encyclopedia)Krebs cycle, series of chemical reactions carried out in the living cell; in most higher animals, including humans, it is essential for the oxidative metabolism of glucose and other simple sugars. The...