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What is the mass of the activity?

  1. Sep 29, 2015 #1
    1. The problem statement, all variables and given/known data
    what is the mass in g of the activity?
    (a)1μCi 241Am

    2. Relevant equations
    A = λN
    λ = ln2 / T1/2

    3. The attempt at a solution
    A = λN

    1μCi = λN

    N=1μCi/λ

    N = ( x /241 mol) × (6.022 × 1023 nuclei mol-1 )

    1μCi/λ=( x /241 mol) × (6.022 × 1023 nuclei mol-1 )

    X=1μCi (241)/λ(6.022× 1023)

    λ = ln2 / T1/2

    λ = ln2/ 432.2 yr

    λ =5.09x10-11 S-1

    X=1μCi (241)/( 5.09x10-11 )*(6.022× 1023)
    x=2.4 x10^-7

    there is something wrong!
     
  2. jcsd
  3. Oct 5, 2015 #2
    Why did you write this equation? Your previous equation is all you need. You want to find N and you know the activity and λ.
     
  4. Oct 6, 2015 #3
    You need to know that 1 Ci is 3.7E10 disintegrating nuclei per sec.
     
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