Question

Identify the group number in the periodic table of X a representative element, in each of the followings ionic compounds Al2X3

Answer 1

In the ionic compound Al2X3:
The group no. of element X is 16

Answer 2

Since Al2X3 is a compound and if we see it with regard to valency rule then :-

Al ( Aluminium ) = 3 as valency
X = 2 as valency
Hence , its group number will be 2.

Hope it helps....