Ncert Exercises & Solutions

Sometimes a radioactive nucleus decays into a nucleus which itself is radioactive. An example is :

$^{38} Sulphur \to_{= 2.48 h}^{half - life}^{38} Cl \to_{= 0.62 h}^{half - life}^{38} Ar (stable)$

Assume that we start with 1000 $^{38} S$ nuclei at time t = 0. The number of $^{38} Cl$ is of count zero at t = 0 and will again be zero at t = $\infty$ . At what value of t, would the number of counts be a maximum?