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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...

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...

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...

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...

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...

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...

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...

ethylene

(Encyclopedia)ethylene ĕthˈēn [key], H2C=CH2, a gaseous unsaturated hydrocarbon. It is the simplest alkene. Ethylene is colorless, has a faint odor, and has a slightly sweet taste; it melts at −169.4℃ and bo...

aniline

(Encyclopedia)aniline ănˈəlĭn [key], C6H5NH2, colorless, oily, basic liquid organic compound; chemically, a primary aromatic amine whose molecule is formed by replacing one hydrogen atom of a benzene molecule w...