A radioactive substance ${ }_{88} X^{228}$ (IIA) emits $3 \alpha$ and $3 \beta$ particles to form " $Y$ ".…
A radioactive substance ${ }_{88} X^{228}$ (IIA) emits $3 \alpha$ and $3 \beta$ particles to form " $Y$ ". To which group of long form of the periodic table does " $Y$ " belong ?