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from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The uranium isotope with mass number 235 and half-life 7.04 × 108 years, fissionable with slow neutrons and capable in a critical mass of sustaining a chain reaction that can proceed explosively with appropriate mechanical arrangements.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a uranium isotope with mass number 235; capable of sustaining chain reactions


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