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hydrogen chloride

(Encyclopedia)hydrogen chloride, chemical compound, HCl, a colorless, poisonous gas with an unpleasant, acrid odor. It is very soluble in water and readily soluble in alcohol and ether. It fumes in moist air. It is...

neutralization

(Encyclopedia)neutralization, chemical reaction, according to the Arrhenius theory of acids and bases, in which a water solution of acid is mixed with a water solution of base to form a salt and water; this reactio...

Tasaday

(Encyclopedia)Tasaday, alleged band of 25 hunter-gatherers living in the Philippine rain forest, purportedly contacted by Westerners for the first time in 1971 in southern Mindanao (Cotabato Province). They reporte...

tannin

(Encyclopedia)tannin, tannic acid, or gallotannic acid, astringent vegetable product found in a wide variety of plants. Sources include the bark of oak, hemlock, chestnut, and mangrove; the leaves of certain sumac...

precipitation, in meteorology

(Encyclopedia)precipitation, in meteorology, condensed moisture that falls to the surface of the earth in the form of rain, sleet, snow, hail, frost, or dew. ...

monkeypod

(Encyclopedia)monkeypod: see rain tree.

Palawan

(Encyclopedia)Palawan päläˈwän [key], island (1990 pop. 528,287), 4,550 sq mi (11,785 sq km), 5th largest of the Philippines, N of Borneo and between the Sulu Archipelago and the South China Sea. Lumbering is a...

acids and bases

(Encyclopedia)acids and bases, two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Another theory that provides a very broad ...

Great Smoky Mountains

(Encyclopedia)Great Smoky Mountains, part of the Appalachian system, on the N.C.–Tenn. border; highest range E of the Mississippi and one of the oldest uplands on earth. The mountains are named for the smokelike ...

United Nations Conference on Environment and Development

(Encyclopedia)United Nations Conference on Environment and Development (UNCED) or Earth Summit, an 11-day meeting held in June, 1992, in Rio de Janeiro, Brazil, to discuss the global conflict between economic devel...