Columbia Encyclopedia

Search results

500 results found

oxygen

(Encyclopedia)oxygen, gaseous chemical element; symbol O; at. no. 8; interval in which at. wt. ranges 15.99903–15.99977; m.p. −218.4℃; b.p. −182.962℃; density 1.429 grams per liter at STP; valence −2. T...

phosphorus

(Encyclopedia)phosphorus fŏsˈfərəs [key] [Gr.,=light-bearing], nonmetallic chemical element; symbol P; at. no. 15; at. wt. 30.97376; m.p. 44.1℃; b.p. about 280℃; sp. gr. 1.82 at 20℃; valence −3, +3, or ...

Sidoarjo mudflow

(Encyclopedia)Sidoarjo mudflow or Lusi [Lumpur Sidoarjo, Bahasa Indonesia, = Sidoarjo mud], mud volcano, Sidoarjo regency, central East Java prov., Indonesia, 20 mi (30 km) S of Surabaya. In May, 2006, a hot mu...

Democritus

(Encyclopedia)Democritus dĭmŏkˈrĭtəs [key], c.460–c.370 b.c., Greek philosopher of Abdera; pupil of Leucippus. His theory of the nature of the physical world was the most radical and scientific attempted up ...

triggerfish

(Encyclopedia)triggerfish, any of several species of tropical reef fishes with laterally compressed bodies, heavy scales, and tough skins. They are named for the mechanism of the three spines of the dorsal fin: whe...

valine

(Encyclopedia)CE5 valine vălˈēn [key], organic compound, one of the 22 α-amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is one of several essential am...

potassium chloride

(Encyclopedia)potassium chloride, chemical compound, KCl, a colorless or white, cubic, crystalline compound that closely resembles common salt (sodium chloride). It is soluble in water, alcohol, and alkalies. Potas...

organic food

(Encyclopedia)organic food, food raised without chemicals and processed without additives. Under standards adopted by the U.S. Agriculture Dept. (USDA) in 2000 and fully effective in 2002, synthetic fertilizers and...

foot-and-mouth disease

(Encyclopedia)foot-and-mouth disease or hoof-and-mouth disease, highly contagious disease almost exclusive to cattle, sheep, swine, goats, and other cloven-hoofed animals. It is caused by a virus, specifically an a...

hydrogen peroxide

(Encyclopedia)hydrogen peroxide, chemical compound, H2O2, a colorless, syrupy liquid that is a strong oxidizing agent and, in water solution, a weak acid. It is miscible with cold water and is soluble in alcohol an...