The half-life of radioactive $C^{14}$ is $5760 \ years$. In how many years will a $200 \ mg$ sample of $C^{14}$ be reduced to $25 \ mg$?

If the quantity of a radioactive element is doubled,then its rate of disintegration per unit time will be

$A$ radioactive isotope has a $t_{1/2}$ of $10 \ days$. If today $125 \ g$ of it is left,what was its weight $40 \ days$ earlier?

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

The rate of radioactive disintegration at an instant for a radioactive sample of half-life $2.2 \times 10^{9} \ s$ is $10^{10} \ s^{-1}$. The number of radioactive atoms in that sample at that instant is:

If $12 \ g$ of a sample is taken,and $6 \ g$ of the sample decays in $1 \ hr$,the amount of the sample showing decay in the next hour is ........ $g$.