* Understand the Formulas:

* FeX: This indicates that one atom of iron (Fe) combines with one atom of element X.

* Fe₂X₃: This indicates that two atoms of iron (Fe) combine with three atoms of element X.

* Identify the Charges:

* In FeX, iron has a +2 charge to balance the charge of X.

* In Fe₂X₃, iron has a +3 charge to balance the charge of the three X atoms.

* Deduce the Charge of X:

* Since the charge of X must balance the charge of iron, in FeX, X has a -2 charge.

* In Fe₂X₃, each X atom has a -2 charge (3 atoms x -2 charge/atom = -6, balanced by +6 from the two iron atoms).

* Determine the Group:

* Elements with a -2 charge in their common ionic form belong to Group 16 (VIA), also known as the chalcogens.

Therefore, element X likely belongs to Group 16 of the periodic table.