Arrange by its radius:
8O, 8O2-, 9F, 9F-, 10Ne, 11Na, 11Na+, 12Mg, 12Mg2+
I understand the concept:
1. More electron shells, bigger the atom/ion
2. If atom/ion has same number of electron shells, then atom/ion with more proton has smaller radius
3. Anion radius > atom radius and Cation radius < atom radius
But I am not sure about the PRIORITY. And if I arrange with the concept, the result is wrong because according to radius data in wiki we know that the order of radius is:
Na > Mg > O2- > F- > Na+ > Mg2+ > O > F > Ne
What priority if we want arrange atom and ion by its radius?
In my case, how can we say Mg2+ radius is bigger than O radius? Because according to the concept this is a contradiction: Mg2+ has more protons so Mg2+ should have smaller radius than O?