Ionic Atmosphere is a concept employed in Debye-Hückel theory which explains the conductivity behaviour of electrolytic solutions. It can be generally defined as the area at which a charged entity is capable of attracting an entity of the opposite charge.

Asymmetry, or Relaxation effect

If an electrical potential is applied to an electrolytic solution, a positive ion will move towards the negative electrode and drag along an entourage of negative ions with it. The more concentrated the solution, the closer these negative ions are to the positive ion and thus the greater the resistance experienced by the positive ion. This influence on the speed of an ion is known as the "Asymmetry effect" because the ionic atmosphere moving around the ion is not symmetrical; the charge density behind is greater than in the front, slowing the motion of the ion.

Electrophoretic effect

This is another factor which slows the motion of ion

Ion

An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...

s within a solution. It is the tendency of the applied potential to move the ionic atmosphere itself. This drags the solvent molecules along because of the attractive forces between ions and solvent

Solvent

A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

molecules. As a result, the central ion at the centre of the ionic atmosphere is influenced to move towards the pole opposite its ionic atmosphere. This inclination retards its motion.