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table tennis

(Encyclopedia)table tennis, game played, usually indoors, by two or four players; it is more or less a miniature form of lawn tennis. It is also called Ping-Pong, after the trade name that a manufacturer adopted (c...

water table

(Encyclopedia)water table, the top zone of soil and rock in which all voids are saturated with water. The level of the water table varies with topography and climate, and depends on the degree to which the groundwa...

Round Table

(Encyclopedia)Round Table, in Arthurian legend, the table at which King Arthur and his knights held court. It was allegedly fashioned at the behest of Arthur to prevent quarrels among the knights over precedence. A...

Döbereiner, Johann Wolfgang

(Encyclopedia)Döbereiner, Johann Wolfgang yōˈhän vôlfˈgäng döˈbərīnər [key], 1780–1849, German chemist. From 1810 he was professor of the Univ. of Jena. He is known especially for his discovery of sim...

nonmetal

(Encyclopedia)nonmetal, chemical element possessing certain properties by which it is distinguished from a metal. In general, this distinction is drawn on the basis that a nonmetal tends to accept electrons and for...

nihonium

(Encyclopedia)nihonium nĭhōˈnēəm [key], artificially produced radioactive chemical element; symbol Nh; at. no. 113; mass number of most stable isotope 284; m.p., b.p., sp. gr., and valence unknown. Situated in...

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...

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...

selenium

(Encyclopedia)selenium səlēˈnēəm [key], nonmetallic chemical element; symbol Se; at. no. 34; at. wt. 78.96; m.p. 217℃; b.p. about 685℃; sp. gr. 4.81 at 20℃; valence −2, +4, or +6. Selenium is directly ...

californium

(Encyclopedia)californium kălˈĭfôrˌnēəm [key] [from California], artificially produced, radioactive metallic chemical element; symbol Cf; at. no. 98; mass no. of most stable isotope 251; m.p. about 900℃; b...