The half of a radioactive substance is 25 minutes The time between $50 \%$ decay and $87.5 \%$ decay of the…

The half of a radioactive substance is 25 minutes The time between $50 \%$ decay and $87.5 \%$ decay of the substance will be
  1. 75 min
  2. $25 \mathrm{~min}$
  3. $37.5 \mathrm{~min}$
  4. $50 \mathrm{~min}$

Solution

For $50 \%$ decay, time is equal to one half-life. For $87.5 \%$ decay, time is three half - lives. $\therefore$ Time interval $\Delta \mathrm{t}=2$ half - lives. $\Delta t=2 \times 25 \mathrm{~min}=50 \mathrm{~min}$

Asked in: MHT CET 2022 (07 Aug Shift 2)

Practice more Structure of Atoms and Nuclei questions on Aicharya