If half life of an element is $69.3$ hours then how much of its percent will decay in $10^{\text {th }}$ to $11^{\text {th }}$ hours. Initial activity $=50\, \mu Ci$
$1$
$2$
$3$
$4$
The half-life of a radioactive substance is $T$. The time taken, for disintegrating $\frac{7}{8}$ th part of its original mass will be
Which of the following is not a mode of radioactive decay
The mean life time of a radionuclide, if its activity decrease by $4\%$ for every $1h$ , would be .......... $h$ [product is non-radioactive i.e. stable]
If half life of radium is $77$ days. Its decay constant in day will be
The fossil bone has a ${}^{14}C:{}^{12}C$ ratio, which is $\left[ {\frac{1}{{16}}} \right]$ of that in a living animal bone. If the halflife of ${}^{14}C$ is $5730\, years$, then the age of the fossil bone is ..........$years$