Columbia Encyclopedia

Search results

454 results found

ruthenium

(Encyclopedia)ruthenium ro͞othēˈnēəm [key], metallic chemical element; symbol Ru; at. no. 44; at. wt. 101.07; m.p. about 2,310℃; b.p. about 3,900℃; sp. gr. 12.41 at 20℃; valence commonly +2, +3, +4, +6, ...

Sade, Donatien Alphonse François, comte de

(Encyclopedia)Sade, Donatien Alphonse François, comte de dônäsyăNˈ älfôNsˈ fräNswäˈ kôNt də säd [key], 1740–1814, French writer and libertine. He is known as the marquis de Sade —the title he held...

Red River Settlement

(Encyclopedia)Red River Settlement, agricultural colony in present Manitoba, North Dakota, and Minnesota. It was the undertaking of Thomas Douglas, 5th earl of Selkirk. Wishing to relieve the dispossessed and impov...

redstart

(Encyclopedia)redstart, common name for an Old World thrush of the genus Phoenicurus, family Turdidae. A small, slender-legged songbird, it is found in woodlands, parks, and heaths. The European redstart, P. phoeni...

marmot

(Encyclopedia)marmot, ground-living rodent of the genus Marmota, of the squirrel family, closely related to the ground squirrel, prairie dog, and chipmunk. Marmots are found in Eurasia and North America; the best-k...

gopher

(Encyclopedia)gopher or pocket gopher, name for the burrowing rodents of the family Geomyidae, found in North America and Central America. The gopher is gray, buff, or dark brown. Its combined head and body length ...

protactinium

(Encyclopedia)protactinium prōˌtăktĭnˈēəm [key], radioactive chemical element; symbol Pa; at. no. 91; mass number of most stable isotope 231; m.p. greater than 1,600℃; b.p. 4,026℃; sp. gr. 15.37 (calcula...

oryx

(Encyclopedia)oryx ôrˈĭks [key], name for several small, horselike antelopes, genus Oryx, found in deserts and arid scrublands of Africa and Arabia. They feed on grasses and scrub and can go without water for lo...

owl

(Encyclopedia)owl, common name for nocturnal birds of prey found on all continents. Owls superficially resemble short-necked hawks, except that their eyes are directed forward and are surrounded by disks of radiati...

gallium

(Encyclopedia)gallium gălˈēəm [key], metallic chemical element; symbol Ga; at. no. 31; at. wt. 69.723; m.p. 29.78℃; b.p. 2,403℃; sp. gr. 5.904 at 29.6℃ (solid), 6.095 at 29.8℃ (liquid); valence +2 or +3...