what does mean by net charge on ion
We are taking the example of compound: CaSO4 (Calcium sulphate)
It is made up to two ions: Ca+2 and (SO4)-2
Ca+2 is a single atom ion, so it is called a monoatomic ion. This ion has a positive charge, so it is called a monoatomic cation.
And (SO4)-2 has two atoms. so it is called diatomic ions. It has negative ion. SO t is called diatomic anoins.