Electrical resistivity and conductivity 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" = <Z>"n"), 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. The magnitude of the potentials and electric fields must be determined by means other than simply finding the net charge density. A common example is to assume that the electrons satisfy the Boltzmann relation: Differentiating this
Negative base For example, the numbers from 100 to 109 have the same representations in decimal and negadecimal. Similarly, and is represented by 10001 in binary and 10001 in negabinary. Some numbers with their expansions in a number of positive and corresponding negative bases are: Note that the base expansions of negative integers have an even number of digits, while the base expansions of the non-negative integers have an odd number of digits. The base expansion of a number can be found by repeated division by , recording the non-negative remainders of formula_3, and concatenating those remainders, starting with the last. Note