Columbia Encyclopedia

Search results

500 results found

hydroxyl group

(Encyclopedia)hydroxyl group hīdrŏkˈsĭl [key], in chemistry, functional group that consists of an oxygen atom joined by a single bond to a hydrogen atom. An alcohol is formed when a hydroxyl group is joined by ...

Hammond

(Encyclopedia)Hammond. 1 City (2020 pop. 77,879), Lake co., extreme NW Ind., bounded by Lake Michigan, the Ill. state line, and the Little Calumet River, and ...

niello

(Encyclopedia)niello nēĕlˈō [key] [Ital. from Latin nigellus=blackish], black metallic alloy of sulfur, copper, silver, and usually lead, used as an inlay on engraved metal. The metal surface is brushed with a ...

voltaic cell

(Encyclopedia)voltaic cell, a simple device with which chemical energy is converted into electrical energy. Two dissimilar metals (e.g., copper and zinc) are immersed in an electrolyte (e.g., a dissolved sulfate). ...

photoengraving

(Encyclopedia)photoengraving, photomechanical process in the graphic arts, used principally for reproducing illustrations. The subject is photographed, and the image is recorded on a sensitized metal plate, which i...

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 ...

Erlanger

(Encyclopedia)Erlanger, city (2020 pop. 19,611), Kenton co., N central Ky.; inc. 1897. Its manufactures include chemicals, sheet metal, medical supplies, and sports a...

Southbridge

(Encyclopedia)Southbridge, town (1990 pop. 17,816), Worcester co., S Mass., on the Quinebaug River; settled 1730, inc. 1816. Chemicals, tools, metal products, and clothing are manufactured. ...

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...

rhodium

(Encyclopedia)rhodium rōˈdēəm [key], metallic chemical element; symbol Rh; at. no. 45; at. wt. 102.90550; m.p. about 1,966℃; b.p. 3,727±100℃; sp. gr. 12.41 at 20℃; valence +2, +3, +4, +5, or +6. Rhodium ...