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  • Radioactive isotope | Description, Uses, Examples | Britannica
    There are several sources of radioactive isotopes Some radioactive isotopes are present as terrestrial radiation Radioactive isotopes of radium, thorium, and uranium, for example, are found naturally in rocks and soil Uranium and thorium also occur in trace amounts in water
  • Isotope | Examples Definition | Britannica
    isotope, one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties Every chemical element has one or more isotopes
  • Cobalt-60 | Uses Radiation | Britannica - Encyclopedia Britannica
    cobalt-60, radioactive isotope of cobalt used in industry and medicine Cobalt-60 is the longest-lived radioactive isotope of cobalt, with a half-life of 5 27 years It is produced by irradiating the stable isotope cobalt-59 with neutrons in a nuclear reactor
  • Tritium | Radioactive, Hydrogen, Decay | Britannica
    tritium, (T, or 3 H), the isotope of hydrogen with atomic weight of approximately 3 Its nucleus, consisting of one proton and two neutrons, has triple the mass of the nucleus of ordinary hydrogen
  • Isotope - Atomic, Radioactive, Stable | Britannica
    Isotope - Atomic, Radioactive, Stable: The composition of any object can be given as a set of elemental and isotopic abundances One may speak, for example, of the composition of the ocean, the solar system, or indeed the Galaxy in terms of its respective elemental and isotopic abundances Formally, the phrase elemental abundances usually
  • Uranium-235 (U-235) | Definition, Uses, Half-Life, Facts | Britannica
    Uranium-235 (U-235), radioactive isotope of the element uranium with a nucleus containing 92 protons and 143 neutrons Uranium-235 is the only naturally occurring fissile material; that is, the uranium-235 nucleus undergoes nuclear fission when it collides with a slow neutron (a neutron with a
  • Isotope - Variations, Abundances, Elements | Britannica
    Isotope - Variations, Abundances, Elements: Although isotopic abundances are fairly constant throughout the solar system, variations do occur Variations in stable isotopic abundances are usually less than 1 percent, but they can be larger Whatever their size, they provide geologists and astronomers with valuable clues to the histories of the
  • Fissile material | Uranium-235, Plutonium-239 Nuclear Reactors . . .
    fissile material, in nuclear physics, any species of atomic nucleus that can undergo the fission reaction The principal fissile materials are uranium-235 (0 7 percent of naturally occurring uranium), plutonium-239, and uranium-233, the last two being artificially produced from the fertile materials uranium-238 and thorium-232, respectively A fertile material, not itself capable of undergoing
  • Nuclear reactor - Fissile, Fertile, Reactors | Britannica
    Prominent sources of these nuclides are thorium-232 (232 Th), uranium-238 (238 U), and plutonium-240 (240 Pu), which are known as fertile materials owing to their ability to transform into fissile materials
  • Definition, Types, Applications, Facts - Britannica
    An example is the decay (symbolized by an arrow) of the abundant isotope of uranium, 238 U, to a thorium daughter plus an alpha particle: Given for this and subsequent reactions are the energy released ( Q ) in millions of electron volts (MeV) and the half-life ( t 1⁄2 )





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