The half life of a radioactive substance is $20$ minutes. The approximate time interval $(t_2 -t_1)$ between the time $t_2$ when $3/4$ of it has decayed and time $t_1$ when $1/4$ of it had decayed is
$\frac{{20}}{{\ln 2}}\min$
$\frac{{20\ln 3}}{{\ln 2}}\min$
$20$ $min$
$20\ln 2\min$
How much mass of uranium to be destroyed per minute to operate a nuclear reactor of $600\,MW$
The activity $R$ of an unknown radioactive nuclide is measured at hourly intervals. The results found are tabulated as follows:
$t(h)$ | $0$ | $1$ | $2$ | $3$ | $4$ |
$R(MBq)$ | $100$ | $35.36$ | $12.51$ | $4.42$ | $1.56$ |
$(i)$ Plot the graph of $R$ versus $t$ and calculate half-life from the graph.
$(ii)$ Plot the graph of $\ln \left( {\frac{R}{{{R_0}}}} \right) \to t$ versus $t$ and obtain the value of half-life from the graph.
The activity of a radioactive material is $2.56 \times 10^{-3} \,Ci$. If the half life of the material is $5$ days, after how many days the activity will become $2 \times 10^{-5} \,Ci$ ?
The sample of a radioactive substance has $10^6$ nuclei. Its half life is $20 \,s$. The number of nuclei that will be left after $10 \,s$ is nearly ...... $\times 10^5$
$x$ fraction of a radioactive sample decay in $t$ time. How much fraction will decay in $2t$ time