Q. The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an

Solution:

${ }_{z} X ^{A} \xrightarrow{\alpha} {}_{Z _2} Y ^{A-4} \xrightarrow{2 \beta ^-} {}_{Z -2+2} Z ^{ A -4}$
$\therefore $ the resultant daughter is an isotope of parent nucleus.