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uranium

(Encyclopedia)uranium yo͞orāˈnēəm [key], radioactive metallic chemical element; symbol U; at. no. 92; mass number of most stable isotope 238; m.p. 1,132℃; b.p. 3,818℃; sp. gr. 19.1 at 25℃; valence +3, +4...

ethanol

(Encyclopedia)ethanol ĕthˈənōlˌ [key] or ethyl alcohol, CH3CH2OH, a colorless liquid with characteristic odor and taste; commonly called grain alcohol or simply alcohol. Ethanol is used extensively as a solv...

protozoan

(Encyclopedia)protozoan prōˌtəzōˈən [key], informal term for the unicellular heterotrophs of the kingdom Protista. Protozoans comprise a large, diverse assortment of microscopic or near-microscopic organisms ...

epoxy group

(Encyclopedia)epoxy group ĕpˈŏksē [key], in chemistry, functional group that consists of an oxygen atom joined by single bonds to two adjacent carbon atoms, thus forming the three-membered epoxide ring. It is t...

allotropy

(Encyclopedia)allotropy əlŏˈtrəpē [key] [Gr.,=other form]. A chemical element is said to exhibit allotropy when it occurs in two or more forms in the same physical state; the forms are called allotropes. Allot...

Ostwald, Wilhelm

(Encyclopedia)Ostwald, Wilhelm vĭlˈhĕlm ôstˈvält [key], 1853–1932, German physical chemist and natural philosopher, b. Riga, Latvia. He was professor of chemistry and director of the chemical laboratory (18...

Huaynaputina

(Encyclopedia)Huaynaputina, volcano, 15,912 ft (4,850 m) high, Moquegua region, S Peru, in the central Andes. A stratovolcano, it lies on the W rim of the Río Tambo canyon and has several ash cones within its crat...

stereochemistry

(Encyclopedia)stereochemistry, study of the three-dimensional configuration of the atoms that make up a molecule and the ways in which this arrangement affects the physical and chemical properties of the molecule. ...

Bessemer process

(Encyclopedia)CE5 Bessemer converter Bessemer process bĕsˈəmər [key] [for Sir Henry Bessemer], industrial process for the manufacture of steel from molten pig iron. The principle involved is that of oxidati...

Odessa, city, United States

(Encyclopedia)Odessa ōdĕsˈə [key], city (1990 pop. 89,699), seat of Ector co., W Tex.; founded 1881, inc. 1927. Great oil deposits just to the south changed Odessa from a small ranch town into a large and growi...