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livermorium

(Encyclopedia)livermorium, artificially produced radioactive chemical element; symbol Lv; at. no. 116; mass number of most stable isotope 292; m.p., b.p., sp. gr., and valence unknown. Situated in Group 16 of the p...

supercomputer

(Encyclopedia)supercomputer, a state-of-the-art, extremely powerful computer capable of manipulating massive amounts of data in a relatively short time. Supercomputers are very expensive and are employed for specia...

Valencia, autonomous community, Spain

(Encyclopedia)Valencia välānˈthēä [key], autonomous community (2011 pop. 5,009,931), 8,980 sq mi (23,257 sq km), and former kingdom, E Spain, on the Mediterranean. It now comprises the provinces of Alicante/Al...

Zagreb

(Encyclopedia)Zagreb zäˈgrĕb [key], Ger. Agram, Hung. Zágráb, city (2011 pop. 790,017), capital and largest city of Croatia, on the Sava River. Zagreb is Croatia's largest industrial, manufacturing, and financ...

promethium

(Encyclopedia)promethium prōmēˈthēəm [key], artificially produced radioactive chemical element; symbol Pm; at. no. 61; mass no. of most stable isotope 145; m.p. 1,042℃; b.p. 3,000℃ (estimated); sp. gr. unk...

hydrogen

(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...

Tennessee Valley Authority

(Encyclopedia)Tennessee Valley Authority (TVA), independent U.S. government corporate agency, created in 1933 by act of Congress; it is responsible for the integrated development of the Tennessee River basin. The h...

seismology

(Encyclopedia)seismology sīzmŏlˈəjē, sīs– [key], scientific study of earthquakes and related phenomena, including the propagation of waves and shocks on or within the earth by natural or artificially genera...

Iran-Iraq War

(Encyclopedia)Iran-Iraq War, 1980–88, protracted military conflict between Iran and Iraq. It officially began on Sept. 22, 1980, with an Iraqi land and air invasion of western Iran, although Iraqi spokespersons m...

hunting

(Encyclopedia)hunting, act of seeking, following, and killing wild animals for consumption or display. It differs from fishing in that it involves only land animals. Hunting was a necessary activity of early humans...