(a) A current of 0.5 A flowing for six minutes and twenty seconds through two cells in series was found to deposit 0.216 g of silver at the cathode of the first cell and 0.659 g of nickel at the cathode of the second cell. Determine: (i) the quantity of electricity passed through the two cells. (ii) the quantity of electricity needed to deposit 1 g of silver atoms. (iii) the quantity of electricity needed to deposit 1 g of nickel atoms. (Relative atomic masses of silver and nickel are 108 and 59, respectively.)