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silicon

(Encyclopedia)silicon, nonmetallic chemical element; symbol Si; at. no. 14; interval in which at. wt. ranges 28.084–28.086; m.p. 1,410℃; b.p. 2,355℃; sp. gr. 2.33 at 25℃; valence usually +4. Silicon is the ...

taxation

(Encyclopedia)taxation, system used by governments to obtain money from people and organizations. The revenue collected is used by the government to support itself and to provide public services. Aside from being r...

Theodosius I

(Encyclopedia)Theodosius I or Theodosius the Great, 346?–395, Roman emperor of the East (379–95) and emperor of the West (394–95), son of Theodosius, the general of Valentinian I. He became (375) military gov...

colon cancer

(Encyclopedia)colon cancer, cancer of any part of the colon (often called the large intestine). Colon cancer is the second most common cancer diagnosed in the United States. Epidemiological evidence has shown that ...

eugenics

(Encyclopedia)eugenics yo͞ojĕnˈĭks [key], study of human genetics and of methods to improve the inherited characteristics, physical and mental, of the human race. Efforts to improve the human race through bette...

tunicate

(Encyclopedia)tunicate to͞oˈnəkĭt [key], marine animal of the phylum Chordata, which also includes the vertebrates. The adult form of most tunicates (also called urochordates) shows no resemblance to vertebrate...

Priestley, Joseph

(Encyclopedia)Priestley, Joseph, 1733–1804, English theologian and scientist. He prepared for the Presbyterian ministry and served several churches in England as pastor but gradually rejected orthodox Calvinism a...

Gallic Wars

(Encyclopedia)Gallic Wars gălˈĭk [key], campaigns in Gaul led by Julius Caesar in his two terms as proconsul of Cisalpine Gaul, Transalpine Gaul, and Illyricum (58 b.c.–51 b.c.). Caesar's first campaign was to...

Anthony, Susan Brownell

(Encyclopedia)Anthony, Susan Brownell, 1820–1906, American reformer and leader of the woman-suffrage movement, b. Adams, Mass.; daughter of Daniel Anthony, Quaker abolitionist. From the age of 17, when she was a ...

antimony

(Encyclopedia)antimony ănˈtĭmōˌnē [key] [Lat. antimoneum], semimetallic chemical element; symbol Sb [Lat. stibium,=a mark]; at. no. 51; at. wt. 121.760; m.p. 630.74℃; b.p. 1,750℃; sp. gr. (metallic form) ...