To calculate the formal charge of sulfur S in the sulfate ion SO4^2- , we can use the following formula:Formal charge = Valence electrons of the atom - Non-bonding electrons - 1/2 x Bonding electrons Sulfur is in group 16 of the periodic table and has 6 valence electrons. In the sulfate ion, sulfur is bonded to four oxygen atoms through double bonds, which means there are 8 bonding electrons 4 bonds x 2 electrons per bond . Sulfur has no non-bonding electrons in this case.Now, we can plug these values into the formula:Formal charge of S = 6 - 0 - 1/2 x 8 Formal charge of S = 6 - 4Formal charge of S = +2So, the formal charge of sulfur S in the sulfate ion SO4^2- is +2.