Columbia Encyclopedia

(Encyclopedia) Java jäˈvə [key], island (1990 pop. 107,525,520), c.51,000 sq mi (132,090 sq km), Indonesia, S of Borneo, from which it is separated by the Java Sea, and SE of Sumatra across Sunda Strait. Although...

(Encyclopedia)  CE5 A. Canal systems of the three morphological types of sponges B. Internal anatomy of an asconoid sponge, representative of the phylum Porifera Porifera pōrĭfˈərə [key] [Lat.,=pore bearer],...

(Encyclopedia) lead, metallic chemical element; symbol Pb [Lat. plumbum]; at. no. 82; at. wt. 207.2; m.p. 327.502℃; b.p. about 1,740℃; sp. gr. 11.35 at 20℃; valence +2 or +4. One of the oldest metals used by h...

(Encyclopedia) ecology, study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of ...

(Encyclopedia) petroleum, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth; it is also called crude oil. It consists principally of a mixture of hydrocarbons, with t...

(Encyclopedia) forest, a dense growth of trees, together with other plants, covering a large area of land. The science concerned with the study, preservation, and management of forests is forestry. A forest is an ec...

(Encyclopedia) salt, chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Salts are also prepared by methods other than neutralization. A metal can c...

(Encyclopedia) colloid kŏlˈoid [key] [Gr.,=gluelike], a mixture in which one substance is divided into minute particles (called colloidal particles) and dispersed throughout a second substance. The mixture is also...

(Encyclopedia) protein, any of the group of highly complex organic compounds found in all living cells and comprising the most abundant class of all biological molecules. Protein comprises approximately 50% of cellu...

(Encyclopedia) pollution, contamination of the environment as a result of human activities. The term pollution refers primarily to the fouling of air, water, and land by wastes (see air pollution; water pollution; s...