The membrane that surrounds a certain type of living cell has a surface area of 3.9 x 10-9 m2 and a thickness of 2.0 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.4. (a) The potential on the outer surface of the membrane is +80.0 mV greater than that on the inside surface. How much charge resides on the outer surface? (b) If the charge in part (a) is due to K+ ions (charge +e), how many such ions are present on the outer surface?