$1.0 \, g$ of a radioactive isotope was found to reduce to $125 \, mg$ after $24 \, hours$. The half-life of the isotope is $....... \, hours$.

$A$ certain nuclide has a half-life of $25 \ min$. If one starts with $100 \ g$ of it,how much of it will remain at the end of $100 \ min$?

$A$ radioactive element has a half-life of $20 \ \text{minutes}$. How much time should elapse before the element is reduced to $\frac{1}{8}$th of the original mass? (Answer in $\text{minutes}$)

In the case of a radioisotope,the value of $T_{1/2}$ and $\lambda$ are identical in magnitude. The value is

The half-life of a radioactive isotope is $3 \ hours$. If the initial mass of the isotope were $256 \ g$,the mass of it remaining undecayed after $18 \ hours$ would be ....... $g$. (in $.0$)

$A$ freshly prepared radioactive element has a half-life of $2 \ hr$. It emits radiation whose intensity is $64$ times the permissible safe level. The minimum time after which it would be possible to work with this sample is .......... $hr$.