Which atom is most likely to form a 2+ ion?

Question

Quizplus · Accepted Answer

Calcium (Ca) has two valence electrons in its outermost energy level. Losing these two electrons will result in a full outermost energy level, giving it an octet configuration and a 2+ charge. Scandium (Sc) has three valence electrons, which would form a 3+ ion. Aluminum (Al) also has three valence electrons, which would form a 3+ ion. Oxygen (O) has six valence electrons, which would form a 2- ion. Fluorine (F) has seven valence electrons, which would form a 1- ion.

Which Atom Is Most Likely to Form a 2+ Ion