Question

Why does magnesium for `Mg^(2+)` cations and not `Mg^(6-)` anions?

Answer 1

Because magnesium is a metallic element that tends to loss electron to achieve stability.

Explanation:

Magnesium is under group 2 that also has a valence electron of 2. To achieve stability and to follow the octet rule, these 2 electrons in the outer shell will be removed making this atom into an ion with a 2+ charge.

`Mg^-6` is impossible in this case, because only nonmetallic elements gain electron to achieve stability.

Thus, magnesium has the ionic symbol of `Mg^(2+)`.