Say you have two conductors and there is a dielectric material between them (a capacitor with a dielectric). The field will the polarize the atoms in the dielectric in such away that the potential difference between the two conductors is weakened. Thus a capacitor with a dielectric between it's conducting surfaces can practically store more charge at a given potential. This is, as I understand it, what the effect of polarization is. 1) Is that correct? 2) To polarize a material you do work, as you are pulling the electrons away from the nucleus. This extra work must go into the potential difference between - and + - i.e. it must be associated with how difficult it is to pull electrons from + to -. Does all the above mentioned, which implies that separating charges gets easier with polarization, account for this "extra" work?