A physics student connects two identical parallel-plate capacitors with a capacitance of 4 μF to a battery with a voltage difference of 10 V, either in series or in parallel. The two plates are separated by a distance of 1mm.  Determine i) the ratio of the energy stored (U_series/U_parallel). ii) the ratio of the maximum amount of charge stored (Q_series/Q_parallel), and iii) the ratio of the electric field (E_series/E_parallel) between the two plates.