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Onsager, Lars

(Encyclopedia)Onsager, Lars, 1903–76, American physical chemist, b. Oslo, Ph.D. Yale, 1935. Onsager taught at Brown Univ. from 1928 to 1933 and was on the faculty at Yale from 1933 until his retirement in 1972. H...

isomorphism

(Encyclopedia)isomorphism īˌsəmôrˈfĭzəm [key], of minerals, similarity of crystal structure between two or more distinct substances. Sodium nitrate and calcium sulfate are isomorphous, as are the sulfates of...

Houston

(Encyclopedia)Houston, city (2020 pop. 2,304,580), seat of Harris co., SE Tex., a deepwater port on the Houston Ship Channel; inc. 1837. Harrisburg (now part of Hou...

Permian period

(Encyclopedia)Permian period pûrˈmēən [key] [from Perm, Russia], sixth and last period of the Paleozoic era (see Geologic Timescale, tablegeologic timescale, table) from 250 to 290 million years ago. Many ma...

fluoride

(Encyclopedia)fluoride, a salt of hydrofluoric acid; see hydrogen fluoride. See also fluoridation; fluorine. ...

Chandler, city, Arizona

(Encyclopedia)Chandler, city (2020 pop. 275,987), Maricopa co., S central Ariz., in the Salt River valley; inc. 1920. It is both a residential community and a center ...

flame

(Encyclopedia)flame, phenomenon associated with the chemical reaction of a gas that has been heated above its kindling temperature with some other gas, usually atmospheric oxygen (see combustion). The heat and ligh...

serotonin

(Encyclopedia)serotonin sĕrˌətōˈnĭn [key], organic compound that was first recognized as a powerful vasoconstrictor occurring in blood serum. It was partially purified, crystallized, and named in 1948, and it...

urea

(Encyclopedia)CE5 urea yo͝oēˈə [key], organic compound that is the principal end product of nitrogen metabolism in most mammals. Urea was the first animal metabolite to be isolated in crystalline form; its c...

Guyton de Morveau, Louis Bernard, Baron

(Encyclopedia)Guyton de Morveau, Louis Bernard, Baron lwē bĕrnärˈ bärôNˈ gētôNˈ də môrvōˈ [key], 1737–1816, French chemist and lawyer. He wrote the chemical section of the Encyclopédie méthodique ...