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Where does the energy from Nuclear Fission comes from?

  1. Feb 11, 2010 #1
    Looking at the fission of Uranium 235, the typical end product will be Barium 141 and Krypton 92, and 3 neutrons.
    From this, we can calculate the energy that the fission gives off, by taking the difference in mass of the product and "reactant", and use the equation of E=mc2.
    But what i see from the above, there isn't any difference in mass. Or am I missing out something here? Someone enlighten me please. Thanks
     
  2. jcsd
  3. Feb 11, 2010 #2

    Matterwave

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    There is a difference in mass, just a very small one...for these calculations, you can not use the usual approximation that mass is just number of protons plus number of neutrons.
    235.0439299-140.914411-91.926156-2(1.0086649)=.186amu

    In energy this is equivalent to 173MeV which is around the 200MeV usually released by U-235 decay.
     
  4. Feb 11, 2010 #3
    OHH...so i have to look all the way down to many decimal places inorder to see the difference in mass...ok..thanks alot...=D
     
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