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Homework Help: Nuclear Chemistry: Kinetics of Radioactive Decay and Radioactive Dating

  1. Apr 25, 2009 #1
    1. The problem statement, all variables and given/known data
    A laboratory rat is exposed to an alpha-radiation source whose activity is 11.3 mCi. What is the activity of the radiation in disintegrations per second? in becquerels? The rat has a mass
    of 315 grams and is exposed to the radiation for 12.3 seconds, absorbing 39% of the emitted alpha particles, each having an energy of 9.10X10^-13 Jeules. Calculate the absorbed does in millirads and grays. If the RBE of the radiation is 9.5, calculate the effective absorbed dose in mrem and Sv.
    Activity of the radiation in disintegrations per second= 4.2X10^8 dis/s
    Activity of the radiation in becquerels= 4.2X10^8 Bq
    2. Relevant equations
    ln (Nt/N0)= -kt
    k= 0.693/t1/2

    3. The attempt at a solution
    I started answering the question by converting the given amount of mCi to Ci.
    Then converting that amount into dis/s and then into Bq.

    After that, I was not exactly sure how to approach part B. A push in the right direction would help
  2. jcsd
  3. Apr 25, 2009 #2
    can anyone at least tell me a method or something for how to figure out how to calculate the absorbed dose in grays?
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