 The good electrical conductivity of plasmas makes their electric fields very small.This results in the important concept of "quasineutrality", which says the density of negative charges is approximately equal to the density of positive charges over large volumes of the plasma ("n"e = ⟨Z⟩>"n"i), but on the scale of the Debye length there can be charge imbalance.In the special case that "double layers" are formed, the charge separation can extend some tens of Debye lengths.