When we have a lewis structure, for instance SO4 2-, I have noticed 2 methods of notating the charge.
1) Place the Lewis Structure in a bracket, with the charge on the outside; the number is first, the charge following.
2) On each atom note the formal charge, and do not use brackets; the number is first, the charge following.
Which is correct? Or is the bracket method used only when you want to combine all the formal charges into one charge?