Final answer:
Ionization percentage increases with dilution because the ratio of ionized to initial substance concentration increases, a concept true for weak acids and bases in aqueous solutions.
Step-by-step explanation:
The statement that % ionization increases with dilution is true. This is because % ionization is the ratio of the amount of a substance ionized to the initial amount of substance before ionization. As the solution becomes more dilute, the initial concentration of the substance decreases, which causes the percent ionization to increase. The relationship between ionization and concentration is not caused by the number of collisions with photons as the reference suggests; that information relates to the photoelectric effect, not ionization of solutions. In the context of acids and bases in aqueous solutions, this concept is explained by the fact that, when a weak acid or base is diluted, the ionization reaction shifts to the right according to Le Chatelier's principle, producing a greater degree of ionization. This does not mean though that the total number of ionized particles increases, just that the proportion of ionized particles to the total number of particles is higher.