$3.8$ days is the half-life period of a sample. After how many days, the sample will become $\frac{{1}}{{8}} \, th$ of the original substance
$11.4$
$3.8$
$3$
None of these
A radioactive sample consists of two distinct species having equal number of atoms $N_0$ initially. The mean-life of one species is $\tau $ and of the other is $5\tau $. The decay products in both cases is stable. The total number of radioactive nuclei at $t = 5\tau $ is
Radioactive element decays to form a stable nuclide, then the rate of decay of reactant $\left( {\frac{{dN}}{{dt}}} \right)$ will vary with time $(t) $ as shown in figure
The $S.I.$ unit of radioactivity is
A radioactive nuclei with decay constant $0.5/s$ is being produced at a constant rate of $100\, nuclei/s$. If at $t\, = 0$ there were no nuclei, the time when there are $50\, nuclei$ is
The phenomenon of radioactivity is