charges are transferred by electrons which we all know but why it cant but it cant be transferred by protons.Well i searched on google where i found similar questions already being asked on many sites.But i ddnt found any answers of them convincing.they were saying that electrons are mobile and similarly protons are busy being nucleons.and similarly someone was saying"By the simple mechanism of separating two things, electrons are pulled out of their Fermi energy levels and into a conduction band to effect charge transference and the creation of a static charge" which i didnt understand at all.