Answer:
The nonmetals in Groups 15, 16, and 17 form ions with charges of 3-, 2-, and 1-, respectively.
Explanation:
The elements of Group 18 (the noble gases) have a complete valence shell of eight electrons.
It is <em>easier</em> for the elements of Groups 15 to 17 <em>to</em> <em>gain</em> three, two, or one electron(s) to get a complete valence shell <em>than it is to lose</em> five, six, or seven valence electrons.
Thus, they form <em>negative ions</em> with charges of 3-, 2-, and 1-, respectively.
The charges <em>do not correspond</em> to the Group numbers of 15 to 17 or the old (pre-1990) Group numbers of 5A to 7A.
