31. Nuclear chemistry question bank (Chemistry)

An element ${ }_{x} A^{y}$ emits $5$ $\alpha$ and $4$ $\beta$ particles to give ${ }_{82} B^{207}$. The number of protons and neutrons in $A$ are respectively

$A$ radioactive isotope having $t_{1/2} = 3 \ days$ was measured after $12 \ days$. If $3 \ g$ of the isotope remains in the container,what was the initial weight of the isotope (in $g$)?