With elements of which column would you expect column 2 elements to unite in a 1-to1 ratio?

Explanation

Column 2 elements have two extra electrons in their outer shells.  The elements of column 16 lack two electrons from having full shells.

The discussion of the number of electrons allowed in various orbits and the methods by which atoms combine to form molecules is not always as simple as indicated here.  These simple methods work only for atoms of small atomic number.