Final answer:
Alkaline earth metals typically form 2+ charge ions by losing two valence electrons, exemplified by calcium becoming Ca²⁺.
Step-by-step explanation:
The elements that typically form ions with a 2+ charge are the alkaline earth metals. These include beryllium, magnesium, calcium, strontium, barium, and radium, which are all located in group 2 of the periodic table.
The alkaline earth metals easily lose two electrons to form cations as they have two valence electrons in their outermost shell. A perfect example is calcium (Ca), which loses two electrons to become Ca²⁺, resulting in a cation that is isoelectronic with the noble gas argon (Ar).