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compound

(Encyclopedia)compound, in chemistry, a substance composed of atoms of two or more elements in chemical combination, occurring in a fixed, definite proportion and arranged in a fixed, definite structure. A compound...

palm

(Encyclopedia)palm, common name for members of the Palmae, a large family of chiefly tropical trees, shrubs, and vines. Most species are treelike, characterized by a crown of compound leaves, called fronds, termina...

Hubble's law

(Encyclopedia)Hubble's law, in astronomy, statement that the distances between galaxies (see galaxy) or clusters of galaxies are continuously increasing and that therefore the universe is expanding. Hubble's law ...

Hannibal, Carthaginian general

(Encyclopedia)Hannibal hănˈəbəl [key], b. 247 b.c., d. 183 or 182 b.c. Carthaginian general, an implacable and formidable enemy of Rome. Although knowledge of him is based primarily on the reports of his enemie...

journalism

(Encyclopedia)journalism, the collection and periodic publication or transmission of news through media such as newspaper, periodical, television, and radio. By broadcasting events such as the Watergate hearin...

Baghdad

(Encyclopedia)Baghdad or Bagdad both: băgˈdăd, bägdädˈ [key], city (2020 pop. 7,144,000), cap...

planetary system

(Encyclopedia)planetary system, a star and all the celestial bodies bound to it by gravity, especially planets and their natural satellites. Until the last decade of the 20th cent., the only planetary system known ...

Arthropoda

(Encyclopedia)Arthropoda ärthrŏpˈədə [key] [Gr.,=jointed feet], largest and most diverse animal phylum. The arthropods include crustaceans, insects, centipedes, millipedes, spiders, scorpions, and the extinct ...

nucleosynthesis

(Encyclopedia)nucleosynthesis or nucleogenesis, in astronomy, production of all the chemical elements from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at...

illustration

(Encyclopedia)illustration, any type of picture or decoration used in conjunction with a text to embellish its appearance or to clarify its meaning. Illustration is as old as writing, with both originating in the p...