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chain reaction

(Encyclopedia)CE5 Chain reaction: A neutron (n) strikes the uranium nucleus (U-235), causing it to split into fission products A and B and release two neutrons. These neutrons can in turn cause further fissions....

isotope

(Encyclopedia)CE5 Isotopes of hydrogen isotope īˈsətōp [key], in chemistry and physics, one of two or more atoms having the same atomic number but differing in atomic weight and mass number. The concept of ...

element

(Encyclopedia)CE5 element, in chemistry, a substance that cannot be decomposed into simpler substances by chemical means. A substance such as a compound can be decomposed into its constituent elements by means o...

Fortune, Robert

(Encyclopedia)Fortune, Robert, 1813–80, British botanist. He traveled in Asia for the Royal Horticultural Society and later for the East India Company and brought back to England a number of chrysanthemums, the J...

multiculturalism

(Encyclopedia)multiculturalism or cultural pluralism, a term describing the coexistence of many cultures in a locality, without any one culture dominating the region. By making the broadest range of human differenc...

Sheepshead Bay

(Encyclopedia)Sheepshead Bay, residential area in S Brooklyn borough of New York City, SE N.Y., on Sheepshead Bay. It was once famous for its horse and automobile races and as a resort center. The bay is an anchora...

cube

(Encyclopedia)cube, in geometry, regular solid bounded by six equal squares. All adjacent faces of a cube are perpendicular to each other; any one face of a cube may be its base. The dimensions of a cube are the le...

chorus, in Greek drama

(Encyclopedia)chorus, in the drama of ancient Greece. Originally the chorus seems to have arisen from the singing of the dithyramb, and the dithyrambic chorus allegedly became a true dramatic chorus when Thespis in...

arithmetic

(Encyclopedia)arithmetic, branch of mathematics commonly considered a separate branch but in actuality a part of algebra. Conventionally the term has been most widely applied to simple teaching of the skills of dea...

Wilkins, Sir George Hubert

(Encyclopedia)Wilkins, Sir George Hubert, 1888–1958, British explorer, b. Australia. He made a number of trips to Antarctica and to the Arctic. Valuable experience gained when he accompanied Vilhjalmur Stefansson...