Answer:
A.1
Explanation:
Fluorine has seven valence electrons and as such, usually forms the F– ion because it gains one electron to satisfy the octet rule. When Mg2+ and F– combine to form an ionic compound, their charges must cancel out. Therefore, one Mg2+ needs two F– ions to balance.
Another explanation:
How many electrons does fluorine need to gain to become stable?
Answer:one electron
In the case of nonmetals such as fluorine, which has seven electrons in the outermost energy level, a more stable state can be achieved by gaining one electron and filling up the outer energy level.
