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Homework Help: Instantaneous Decay rate per unit Volume

  1. Jan 16, 2006 #1
    'A radioactive element has a 0.5 probability of decaying to a more stable element after a particular time-span T.

    What is the instantaneous decay rate per unit volume? In other words determine a general expression for the number of decay events occurring per unit volume between t=t1 and t=t2 as the difference between these two times t2-t1 approaches zero.'

    This is the last part of a group presentation we have to prepare and has us all stumped. Any thoughts?
  2. jcsd
  3. Jan 20, 2006 #2

    Tom Mattson

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    You can interpret that statistically. If each nucleus has a 0.5 probability of decaying within time T, then you would expect half of a sample to have decayed by time T.

    In other words, T is the half-life of the sample.

    Use the standard model for exponential decay. Since they want the number of events per unit volume, I would divide both sides by the volume.
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