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charcoal

(Encyclopedia)charcoal, substance obtained by partial burning or carbonization (destructive distillation) of organic material. It is largely pure carbon. The entry of air during the carbonization process is control...

ozone layer

(Encyclopedia)ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone, located at altitudes of 12–30 mi (19–48 km) above the earth's surface. Ozone in the ozone...

iodine

(Encyclopedia)iodine īˈədīn, –dĭn [key] [Gr.,=violet], nonmetallic chemical element; symbol I; at. no. 53; at. wt. 126.90447; m.p. 113.5℃; b.p. 184.35℃; sp. gr. 4.93 at 20℃; valence −1, +1, +3, +5, o...

battery, electric

(Encyclopedia)CE5 Lead storage cell: At the lead-dioxide electrode, electrons from the circuit combine with lead dioxide and sulfuric acid to form lead sulfate and water. At the spongy-lead electrode, lead react...

respiration

(Encyclopedia)CE5 Respiratory system respiration, process by which an organism exchanges gases with its environment. The term now refers to the overall process by which oxygen is abstracted from air and is tran...

Sanger, Frederick

(Encyclopedia)Sanger, Frederick săngˈər [key], 1918–2013, British biochemist, grad. Cambridge (B.A., 1939; Ph.D., 1943). He continued his research at Cambridge after 1943. He won the 1958 Nobel Prize in Chemis...

citron

(Encyclopedia)citron sĭtˈrən [key], name for a tree (Citrus medica) of the family Rutaceae (orange family), and for its fruit, the earliest of the citrus fruits to be introduced to Europe from Asia. The small ev...

ebony

(Encyclopedia)ebony, common name for members of the Ebenaceae, a family of trees and shrubs widely distributed in warmer climates and in the tropics. The principal genus, Diospyros, includes both ebony and persimmo...

eating disorders

(Encyclopedia)eating disorders, in psychology, disorders in eating patterns that comprise four categories: anorexia nervosa, bulimia, rumination disorder, and pica. Anorexia nervosa is characterized by self-starvat...

azalea

(Encyclopedia)azalea əzālˈyə [key] [Gr.,=dry], any species of the genus Rhododendron, North American and Asian shrubs of the family Ericaceae (heath family) that are distinguished by the usually deciduous leave...