caused by the ability of electrons to flow from one half cell too the other
Explanation:
How is the potential voltage of a redox reaction?
The potential difference is caused by the ability of electrons to flow from one half cell to the other. Electrons are able to move between electrodes because the chemical reaction is a redox reaction. A redox reaction occurs when a certain substance is oxidized, while another is reduced.
The half-cells separate the oxidation half-reaction from the reduction half-reaction and make it possible for current to flow through an external wire.
You have not mention here about those elements but the general concept for this is the: uneven distribution ------> polar even distribution -------> non-polar
