Question 389: Atoms & Nuclei

Question

Two radioactive materials A and B have decay constants $$25 \lambda$$ and $$16 \lambda$$ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of B to that of A will be "e" after a time $$\frac{1}{a \lambda}$$. The value of a is _________.

Accepted Answer

$N_{A}=N_{0} e^{-25 \lambda t}$
$N_{B}=N_{0} e^{-16 \lambda t}$
$\frac{N_{B}}{N_{A}}=e=e^{9 \lambda t}$
$t=\frac{1}{9 \lambda}$

Atoms & Nuclei

Two radioactive materials A and B have decay constants $25 \lambda and 16 \lambda respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of B to that of A will be "e" after a time \frac{1}{a \lambda}$. The value of a is _________.

Choose the correct answer: