In the uranium radioactive series, the initial nucleus is $_{92}{U^{238}}$ and the final nucleus is $_{82}P{b^{206}}$. When the uranium nucleus decays to lead, the number of $\alpha - $ particles emitted will be
$1$
$2$
$4$
$8$
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
Give the equation form of exponential law.
The half life of a radioactive substance is $20$ minutes. The approximate time interval $(t_2 - t_1)$ between the time $t_2$ when $\frac{2}{3}$ of it had decayed and time $t_1$ when $\frac{1}{3}$ of it had decayed is ..........$min$
Half life of a radioactive substance is $T$. The time taken for all the nuclei to disintegrate will be
If half-life of a substance is $3.8\, days$ and its quantity is $10.38\, gm$. Then substance quantity remaining left after $19\, days$ will be ........$gm$