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Nuclear Decay

  1. Apr 26, 2015 #1
    I'm sorry for posting this another thread, but I accidentally posted under to wrong forum initially and could not figure out how to delete it :-(

    1. The problem statement, all variables and given/known data

    Find the missing isotope: Iodine-127 (n, alpha)
    My answer is Sb- 122 but it was wrong.

    Also, how would I go about finding the number of alpha and (negative) beta decay reactions needed to reduce an isotope, if I am not given half life? Please help! I know I am probably making it harder than it has to be!

    2. Relevant equations

    I am having a bit of trouble applying nuclear decay reactions. I understand the differences between alpha, beta, and gamma, but cannot seem to solve the equations 100% of the time. I do not know how I would type out alpha, beta, and gamma here, though. So I will just say that given alpha, I know to subtract, and Beta can be positive or negative. Gamma has no addition or subtraction.

    3. The attempt at a solution

    I wonder if I am just not comprehending what (n,alpha) means. Set up in a way to identify the particles is easy for me, though. As for the question pertaining to the cascade, we never reviewed a problem like that and therefore I would really appreciate someone just offering me a starting point.
  2. jcsd
  3. Apr 26, 2015 #2


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    Staff Emeritus
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    Homework Helper

    The reaction: Iodine-127 (n, alpha) is just a shorthand way or writing the following:

    127I + n → X + α, or in words

    an atom of I-127 when struck by a neutron turns into element X plus one alpha particle.

    You have to identify element X and figure out its atomic weight.

    [If you want access to certain math and Greek alphabet symbols, hit the ∑ at the end of the toolbar in the Reply Box.]
  4. May 16, 2015 #3

    James Pelezo

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    Gold Member

    This post was entered ~ 1-mo ago. Are you still in need of some suggestions? jp
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