Question
The decay constant of a ratio isotope is λ. If A1 and A2 are its activities at times t1 and t2 respectively, te number of nuclei which have decayed during the time (t1-t2)
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A1t1 - A2t2
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A1 - A2
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(A1 - A2)/λ
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λ(A1 - A2)
Solution
C.
(A1 - A2)/λ
A1 = λN1
A2 = λN2
N1 -N2 = [A1 -A2/ λ]
