The capacitance of a capacitor is defined as the charge stored per unit pd. A capacitor is a device designed to store charge as it contains two parallel metal plates next to each other. As electrons move through the battery and are forced from its negative terminal of the battery onto one of the plates. An equal number of electrons leave the other plate to return to the battery via its positive terminal.
Capacitor charging and discharging follow an exponential relationship. At time = the time constant RC, the charge falls to 0.37 of its initial value.
Dielectrics are electrical insulators. They increase the capacitance of a capacitor. The negative ends of the molecules are attracted to the positive plat and vice versa. The molecules rotate and align themselves anti-parallel to the electric field generated between the plates.