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benzaldehyde

(Encyclopedia)benzaldehyde bĕnˌzēnkärˈbənəl [key], C6H5CHO, colorless liquid aldehyde with a characteristic almond odor. It boils at 180℃, is soluble in ethanol, but is insoluble in water. It is formed by ...

plating

(Encyclopedia)plating, application of a plate, or coat, of metal to a surface for decoration, reflection of light, protection against corrosion, or increased wearing quality. The practice is of ancient origin: gild...

metallurgy

(Encyclopedia)metallurgy mĕtˈəlûrˌjē [key], science and technology of metals and their alloys. Modern metallurgical research is concerned with the preparation of radioactive metals, with obtaining metals econ...

gold

(Encyclopedia)gold, metallic chemical element; symbol Au [Lat. aurum=shining dawn]; at. no. 79; at. wt. 196.96657; m.p. 1,064.43℃; b.p. 2,808℃; sp. gr. 19.32 at 20℃; valence +1 or +3. Gold is very ductile and...

alchemy

(Encyclopedia)alchemy ălˈkəmē [key], ancient art of obscure origin that sought to transform base metals (e.g., lead) into silver and gold; forerunner of the science of chemistry. Some scholars hold that it was ...

Roseville

(Encyclopedia)Roseville. 1 City (1990 pop. 44,685), Placer co., N central Calif., a suburb of Sacramento in the foothills of the Sierra; inc. 1909. Marked by rapid growth in the late 20th cent., Roseville is in an ...

thulium

(Encyclopedia)thulium tho͞oˈlēəm [key] [from Thule, an ancient name for Scandinavia], metallic chemical element; symbol Tm; at. no. 69; at. wt. 168.93421; m.p. about 1,545℃; b.p. 1,947℃; sp. gr. 9.3; valenc...

flame test

(Encyclopedia)flame test, test used in the identification of certain metals. It is based on the observation that light emitted by any element gives a unique spectrum when passed through a spectroscope. When a salt ...

Sommerfeld, Arnold Johannes Wilhelm

(Encyclopedia)Sommerfeld, Arnold Johannes Wilhelm ärˈnōlt yōhänˈəs vĭlˈhĕlm zômˈərfĕlt [key], 1868–1951, German physicist and teacher. He received a Ph.D. at Königsburg Univ. in 1891 and was a prof...

tartaric acid

(Encyclopedia)tartaric acid, HO2CCHOHCHOHCO2H, white crystalline dicarboxylic acid. It occurs as three distinct isomers, the dextro-, levo-, and meso- forms. The dextro- and levo- forms are optically active; the me...