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antiparticle
(Encyclopedia)antiparticle, elementary particle corresponding to an ordinary particle such as the proton, neutron, or electron, but having the opposite electrical charge and magnetic moment. Every elementary partic...diffraction
(Encyclopedia)diffraction, bending of waves around the edge of an obstacle. When light strikes an opaque body, for instance, a shadow forms on the side of the body that is shielded from the light source. Ordinarily...lepton
(Encyclopedia)lepton lĕpˈtŏnˌ [key] [Gr.,=light (i.e., lightweight)], class of elementary particles that includes the electron and its antiparticle, the muon and its antiparticle, the tau and its antiparticle, ...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 bomb
(Encyclopedia)hydrogen bomb or H-bomb, weapon deriving a large portion of its energy from the nuclear fusion of hydrogen isotopes. In an atomic bomb, uranium or plutonium is split into lighter elements that togethe...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 ...krypton
(Encyclopedia)krypton krĭpˈtŏn [key] [Gr.,=hidden], gaseous chemical element; symbol Kr; at. no. 36; at. wt. 83.798; m.p. −156.6℃; b.p. −152.3℃; density 3.73 grams per liter at STP; valence usually 0. Kr...radon
(Encyclopedia)radon rāˈdŏn [key], gaseous radioactive chemical element; symbol Rn; at. no. 86; mass no. of most stable isotope 222; m.p. about −71℃; b.p. −61.8℃; density 9.73 grams per liter at STP; vale...curium
(Encyclopedia)curium kyo͝orˈēəm [key], artificially produced radioactive chemical element; symbol Cm; at. no. 96; mass no. of most stable isotope 247; m.p. about 1,340℃; b.p. 3,110℃; sp. gr. 13.5 (calculate...cobalt, chemical element
(Encyclopedia)cobalt, metallic chemical element; symbol Co; at. no. 27; at. wt. 58.9332; m.p. 1,495℃; b.p. about 2,870℃; sp. gr. 8.9 at 20℃; valence +2 or +3. Cobalt is a silver-white, lustrous, hard, brittle...Browse by Subject
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