An atom of an element forms a 2+ ion. in which group on the periodic table could this element be located?
(1) 1 (3) 13
(2) 2 (4) 17

To form a 2+ ion, you need to lose two negatively charged electrons. Because metals have relatively empty outer shells, they lose electrons. Metals are on the left hand side of the table, and in order to lose two electrons, you need to have two electrons to start with. The groups of the table are based on the number of electrons an element has in the outer shell, so Group 2 metals will lose two electrons to gain a 2+ charge