One of the most important single steps in establishing the electrical nature of the forces between atoms was the electrolysis experiments in 1833 by Michael Faraday.

He carried out a series of experiments to study the chemical changes produced when electric currents were passed through solutions and mixtures of chemical substances.

He observed that chemical changes occurred of the type that we have been examining in the preceding section. He made two quantitative observations, now called Faraday's laws:

1. The weight of chemical substance produced in an anode or cathode reaction in an electrolysis cell is proportional to the quantity of electricity passed through the cell.

2. The weights of two different substances produced by the same quantity of electricity are proportional to the equivalent weights of the substances in reactions between them or with other substances.