The amount of $_{53}I^{128}$ $(t_{1/2} = 25 \ minutes)$ left after $50 \ minutes$ will be

The order of a radioactive disintegration reaction is:

The decay profiles of three radioactive species $A$,$B$ and $C$ are given below:
These profiles imply that the decay constants $k_A$,$k_B$ and $k_C$ follow the order:

The Carbon-$14$ dating method is based on the fact that:

The half-life of a radioactive element is $100 \, \text{min}$. The time interval between the stages of $50\%$ and $87.5\%$ decay will be ...... $\text{min}$.

If the disintegration constant is $6.93 \times 10^{-6} \ s^{-1}$,then the half-life of $_{6}C^{14}$ will be: