1. In a Stock system name such as iron(III) sulfate, the Roman numeral tells us (a) how many atoms of Fe are in one formula unit. (b) how many sulfate ions can be attached to the iron atom. (c) the charge on each Fe ion. (d) the total positive charge of the formula unit. 2. Changing a subscript in a correctly written chemical formula (a) changes the number of moles represented by the formula. (b) changes the charges on the other ions in the compound. (c) changes the formula so that it no longer represents the compound it previously represented. (d) has no effect on the formula.