Refer to the illustration of the periodic table to determine which formula is correct.
Mg3O2
Mg2O
MgO2
MgO

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!

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.