Which has a larger radius, the oxygen atom (O) or oxygen ion (O-2) ? Explain.

Question

Isn't the ion bigger because negative ions are bigger than atom's radius. im not sure though.

Answer 1

Yes and yes but the reasoning is no very good. The negative ions are larger than their neutral atom because the electrons, all going into the outer shell (which is already occupied with electrons) repel each other and that takes up more space.