To calculate the formal charge on the oxygen atom in the sulfate ion SO , we can use the following formula:Formal charge = Valence electrons of the atom - Non-bonding electrons - 1/2 Bonding electrons In the sulfate ion, the sulfur atom is bonded to four oxygen atoms through double bonds. Each oxygen atom forms a double bond with the sulfur atom.For oxygen:1. Valence electrons of oxygen = 6 as it is in group 16 of the periodic table 2. Non-bonding electrons = 4 as there are two lone pairs on each oxygen atom 3. Bonding electrons = 4 as there are two bonds formed, and each bond has 2 electrons Now, we can plug these values into the formula:Formal charge = 6 - 4 - 1/2 4 Formal charge = 6 - 4 - 2Formal charge = 0However, this is the formal charge of one oxygen atom in the sulfate ion. Since the overall charge of the sulfate ion is -2, and there are four oxygen atoms, the total negative charge is distributed among the four oxygen atoms. Therefore, each oxygen atom has a formal charge of -1/2. But, formal charges are always whole numbers, so two of the oxygen atoms will have a formal charge of -1, and the other two will have a formal charge of 0.So, the formal charge on an oxygen atom in the sulfate ion SO can be either -1 or 0, depending on which oxygen atom you are considering.