What is the charge on a carbonate ion #(CO_3)##2-#?Compared to the number of protons, how many electrons does the carbonate ion have?
The carbonate dianion MUST have 2 more electrons than it does nuclear protons. Let's see if it does.
The number of nuclear protons are the number of positively charged particles contained in atomic nuclei.
So how many electrons on carbonate? There are 6 from carbon, 24 from oxygen, PLUS 2 extra negatively charged particles from the formal charge on the anion. 32 electronic charges (
Of course this assignment of charge is a formalism; and we would distribute the charge over the oxygen centres by resonance.