Answer:
D. MgO
Explanation:
We need to look at the charge of element. (Look at a periodic table for this)
Mg, which is Magnesium, has a charge of 2+ because it's in the second column, or group, from the left.
O, which is Oxygen, has a charge of 2- because it's in the second column, or group, from the right.
Since Mg is 2+, it's the cation and since O is 2-, it's the anion. We can put these two elements together into an ionic compound.
Mg^(2+) and O^(2-) becomes Mg2O2, where we can cancel the 2s: MgO.
Thus, the answer is D.
Hope this helps!
