What is the ion notation for an atom with 8 protons and 10 electrons?
This is an oxide ion with a negative two charge.
With eight protons, we are necessarily looking at oxygen, but with 10 electrons, the net charge on the ion is minus two.
This charge is written as a superscript in the upper right corner relative to the symbol for oxygen atoms
Closest I can get to the write the symbol in this answer is