Final answer:
Alkaline earth metals from group 2 of the periodic table form ions with a 2+ charge by losing two electrons to achieve a stable electron configuration.
Step-by-step explanation:
The alkaline earth metals, which belong to group 2 of the periodic table, form ions that satisfy the Octet Rule by losing two electrons. This results in a 2+ ionic charge. For example, a neutral calcium atom (Ca) loses two electrons to become a Ca2+, with a stable electron arrangement similar to the noble gas argon (Ar).