JEE Mains · Physics · STD 12 - 13. Nuclei
The half-life of \({ }^{198} {Au}\) is \(3 \,days.\) If atomic weight of \({ }^{198} {Au}\) is \(198\, {g} / {mol}\) then the activity of \(2 \,{mg}\) of \({ }^{198} {Au}\) is ..... \(\times 10^{12}\,disintegration/second\)
- A \(2.67\)
- B \(16.18\)
- C \(6.06\)
- D \(32.36\)
Answer & Solution
Correct Answer
(B) \(16.18\)
Step-by-step Solution
Detailed explanation
\(A =\lambda N\) \(\lambda=\frac{\ln 2}{ t _{1 / 2}}=\frac{\ln 2}{3 \times 24 \times 60 \times 60} sec ^{-1}=2.67 \times 10^{-6} sec ^{-1}\) \(N =\) Number of atoms in \(2 \;mg \;Au\) \(=\frac{2 \times 10^{-3}}{198} \times 6 \times 10^{23}=6.06 \times 10^{15}\)…
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