posted by Dennis .
How is the ionic charge of a group 1A,2A, or 3A ion determined?
Group IA elements have 1 electron in their outer shell.
Group IIA elements have 2 electrons in their outer shell.
Group IIIA elements have 3 electrons in their outer shell.
These elements lose 1, 2, or 3 electrons respectively, leaving ions with a charge of +1, +2, or +3.
If you have the ion ONLY, look at the charge on the ion. The charge WILL BE the charge on the ion.
OR have I not interpreted your question correctly?