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ion, in chemistry
(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...nucleus, in physics
(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...solar system
(Encyclopedia)CE5 Solar system CE5 solar system, the sun and the surrounding planets, natural satellites, dwarf planets, asteroids, meteoroids, and comets that are bound by its gravity. The sun is by far the ...atmosphere
(Encyclopedia)CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...pressure
(Encyclopedia)pressure, in mechanics, ratio of the force acting on a surface to the area of the surface; it is thus distinct from the total force acting on a surface. A force can be applied to and sustained by a si...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...star
(Encyclopedia)star, hot incandescent sphere of gas, held together by its own gravitation, and emitting light and other forms of electromagnetic radiation whose ultimate source is nuclear energy. The universe co...radioactivity
(Encyclopedia)CE5 Effects of a magnetic field on the products of radioactivity CE5 Disintegration series: Radioactive decay of radium-226 into lead-206 radioactivity, spontaneous disintegration or decay of t...nuclear energy
(Encyclopedia)CE5 Graph of binding energy per nucleon as a function of mass number nuclear energy, the energy stored in the nucleus of an atom and released through fission, fusion, or radioactivity. In these pr...Jupiter, in astronomy
(Encyclopedia)Jupiter jo͞oˈpətər [key], in astronomy, 5th planet from the sun and largest planet of the solar system. Astronomers have discovered 79 satellites orbiting Jupiter, but five of those, small sate...Browse by Subject
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