Explanation:
It is known that the atomic number of magnesium is 12 and its electronic distribution is 2, 8, 2. And, in order to attain stability a magnesium atom will tend to lose its valence electrons.
That is, being a metal magnesium atom will lose its 2 valence electrons and hence it forms a [tex]Mg^{2+}[/tex] ion.
Equation for this type of loss is as follows.
[tex]Mg \rightarrow Mg^{2+} + 2e^{-}[/tex]
Therefore, we can conclude that the charge of the ion formed by the [tex]_{12}Mg[/tex] atom is +2.
