Answer
It is not possible to calculate without the value of "m". (e)
Work Step by Step
In order to determine the group which Y belongs, we need to know how many dots are in the symbol for the neutral element.
We can do that by subtracting the number of current dots in the ion, minus its negative charge.
Group = 8 - m
Since "m" is not given, we cannot calculte the original amount of valence electrons, and we cannot find the group Y belongs.
