How many electrons are there in carbonate ion, #CO_3^(2-)#?
The carbonate dianion is
Now, clearly, the ion must contain 2 more electrons, than it does nucular charges.....in one formula unit of
And their presence is clear from the Lewis structure of carbonate anion.....there are 8 inner core electrons, i.e. formally the
And all I have done is considered the atomic numbers of each element....