The number of beta particles emitted by a radioactive substance is twice the number of alpha particl

Question

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

Professor PC Thomas Classes · Answer

Emission of $1 \alpha$ decreases atomic number by 2; $2 \beta$ increases it by 2. Net change in Z is 0 $\Rightarrow$ isotope.