To calculate the formal charge on the central atom sulfur in SO3, we will use the formula:Formal charge = Valence electrons of the atom - Non-bonding electrons - 1/2 Bonding electrons Sulfur S has 6 valence electrons being in group 16 of the periodic table. In the SO3 ion, sulfur is double bonded to three oxygen atoms. Each double bond consists of 2 bonding electrons, so there are a total of 6 bonding electrons around sulfur. Sulfur has no non-bonding electrons in this case.Now, let's plug the values into the formula:Formal charge on S = 6 - 0 - 1/2 6 Formal charge on S = 6 - 3 = +3So, the formal charge on the central sulfur atom is +3.Now, let's determine the overall charge of the SO3 ion. Each oxygen atom has a formal charge of -1 due to the double bond with sulfur. Since there are three oxygen atoms, the total charge from the oxygen atoms is -3. Adding the formal charge of sulfur +3 to the total charge of the oxygen atoms -3 , we get:Overall charge = +3 + -3 = 0However, the ion is SO3, which means it has an overall charge of -2. This discrepancy arises because the Lewis structure of SO3 is a resonance hybrid, and the formal charges calculated are for a single resonance structure. The actual ion has a delocalized charge, and the overall charge is -2, as indicated by the superscript in SO3.