Question

What is the electron dot diagram for magnesium oxide?

Answer 1

Well, magnesium oxide is an ionic species, which we could represent as `Mg^(2+)O^(2-)`.

Explanation:

Elemental magnesium has 12 nuclear protons, `Z=12`. It has 2 valence electrons that are conceived to be lost when it undergoes oxidation to `Mg^(2+)`.

`MgrarrMg^(2+) + 2e^-` `(i)`

Elemental (atomic!) oxygen has 8 electrons, `Z=8`. The oxide anion thus has 10 electrons upon reduction:

`O + 2e^(-) rarr O^(2-)` `(ii)`

So `(i) + (ii)=`

`Mg(s) + 1/2O_2(g) rarr MgO(s)`