They, like the dissertation committee, could not imagine sodium, a metal that violently reacts with water, and chlorine, a gas with toxic properties, existing as independent tragments after sodium chloride dissolved in water. He could explain weak and strong acids by the concentration of the ions, known as percent dissociation today. Fortunately a few of the younger men in the new field of physical chemistry were intrigued by the notion of ions and by Arrhenius' reasoning. His model gained acceptance as the network of young chemists started to explain their results in terms of ions and dissociation. Data continued to support the concept that ionic and polar covalently bonded substances dissociate in water.
Some substances dissociate to a greater extent.
These statements explain the colligitave properties and differences in pH of similar acid concentrations. Bronsted, Lowry, Lewis and others have developed a more general model of acids and bases for non-water solvent systems. We also must be prepared to accept the next model for the dissociation of substances. This source has a fine portrait and biography. The Story of Chemistry, Simon and Schuster, Inc., New York,1930, pp 219 - 241.