The half life period of a radioactive element $X$ is same as the mean life time of another radioactive element $Y$. Initially both of them have the same number of atoms. Then
$X$ and $Y$ have the same decay rate initially
$X$ and $Y$ decay at the same rate always
$Y$ will decay at a faster rate than $X$
$X$ will decay at a faster rate than $Y$
Define the disintegration rate or radioactivity of a sample and obtain the relation $R = \lambda N$ and define its different units.
Activity of a radioactive substance is $R_1$ at time $t_1$ and $R_2$ at time $t_2(t_2 > t_1).$ Then the ratio $\frac{R_2}{R_1}$ is :
A radioactive material has a half-life of $8$ years. The activity of the material will decrease to about $1/8$ of its original value in .......... $years$
Half life of a radioactive substance is $T$. The time taken for all the nuclei to disintegrate will be
Half-life of a radioactive substance is $20$ minutes. Difference between points of time when it is $33\%$ disintegrated and $67\%$ disintegrated is approximately ........... $min$