A nucleus  $_n{X^m}$ emits one $\alpha$ particle and two $\beta$ particles. The resulting nucleus is

Consider the following radioactive decay process 

${ }_{84}^{218} A \stackrel{\alpha}{\longrightarrow} A_1 \stackrel{\beta^{-}}{\longrightarrow} A_2 \stackrel{\gamma}{\longrightarrow} A_3 \stackrel{\alpha}{\longrightarrow} A_4 \stackrel{B^{+}}{\longrightarrow} A_5 \stackrel{\gamma}{\longrightarrow} A_6$

The mass number and the atomic number $A _6$ are given by 

$_1{H^1}{ + _1}{H^1}{ + _1}{H^2} \to X + {\;_{ + 1}}{e^0} + $energy. The emitted particle is

Pauli suggested the emission of nutrino during $\beta^{+}$decay to explain

$^{22}Ne$ nucleus after absorbing energy decays into two $\alpha - $ particles and an unknown nucleus. The unknown nucleus is

An element $A$ decays into element $C$ by a two step process :

$A \to B + {\;_2}H{e^4}$

$B \to C + \;2{e^ - }$

Then