Question

In a radioactive decay chain reaction, ${ }_{90}^{230} Th$ nucleus decays into ${ }_{84}^{214} Po$ nucleus. The ratio of the number of $\alpha$ to number of $\beta^{-}$particles emitted in this process is _____

Answer 1

$ Th _{90}^{230} \rightarrow Po _{84}^{214}+ n _2^4+ m \beta_{-1}^0 $
$ 230=214+4 n $
$ n =\frac{16}{4}=4 $
$90=84+ n \times 2- m \times 1$
$90=84+4 \times 2- m \times 1$
$ m =92-90=2$
Hence $\frac{ n }{ m }=\frac{4}{2}=2$ Ans.