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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...

Castro, Fidel

(Encyclopedia)Castro, Fidel (Fidel Alejandro Castro Ruz) käsˈtrō [key], 1926–2016, Cuban revolutionary, premier of Cuba (1959–76), president of the Council of State and of the Council of Ministers (1976–2...

Kazakhstan

(Encyclopedia)CE5 Kazakhstan or Kazakstan käˌzäkstänˈ [key], officially Republic of Kazakhstan, republic (2015 est. pop. 17,750,000), c.1,050,000 sq mi (2,719,500 sq km), central Asia. It borders on Siberia...

elementary particles

(Encyclopedia)CE5 elementary particles, the most basic physical constituents of the universe. The first subatomic particle to be discovered was the electron, identified in 1897 by J. J. Thomson. After the...

Rajasthan

(Encyclopedia)Rajasthan räˈjəstän [key], state (2001 provisional pop. 56,473,122), 132,150 sq mi (342,269 sq km), NW India, bordered on the west by Pakistan. The capital is Jaipur; other large cities are Ajmer,...

technetium

(Encyclopedia)technetium tĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,200℃; b.p. 4,877�...

seaborgium

(Encyclopedia)seaborgium sēbôrˈgēəm [key], artificially produced radioactive chemical element; symbol Sg; at. no. 106; mass number of most stable isotope 271; m.p., b.p., sp. gr., and valence unknown. Situated...

gluon

(Encyclopedia)gluon, an elementary particle that mediates, or carries, the strong, or nuclear, force. In quantum chromodynamics (QCD), the quantum field theory of strong interactions, the interaction of quarks (to ...