Which of the following is deflected by an electric field?

$A$ radioactive nucleus undergoes $\alpha$-emission to form a stable element. What will be the recoil velocity of the daughter nucleus if $V$ is the velocity of $\alpha$-emission and $A$ is the atomic mass of the radioactive nucleus?

The nucleus ${ }_{Z}^{A} X$ undergoes the series of reactions given below:
${ }_{Z}^{A} X \stackrel{\alpha \text {-decay }}{\longrightarrow} P \stackrel{\beta \text {-decay }}{\longrightarrow} Q \stackrel{\alpha \text {-decay }}{\longrightarrow} R$
The number of neutrons in the nucleus $R$ is

$A$ radioactive material $P$ first decays into $Q$ and then $Q$ decays to non-radioactive material $R$. Which of the following figures represents the time-dependent mass of $P$,$Q$,and $R$?

The nucleus $_{48}^{115}Cd$ after two successive ${\beta ^ - }$ decays will give:

$A$ stationary nucleus of mass number $220$ emits an $\alpha$-particle. If the energy released in the process is $5.5 \, MeV$,find the kinetic energy of the $\alpha$-particle in $MeV$.