Final answer:
Ionic compounds dissociate into ions when they dissolve in water, while polar molecules do not dissociate but disperse evenly in the solution.
Step-by-step explanation:
When ionic compounds dissolve in water, they dissociate into their constituent ions due to the polar nature of water, which allows it to surround and solvate the ions. This is a physical process that breaks the electrostatic forces in the solid ionic compound. In contrast, when polar molecules dissolve in water, they typically do not dissociate into ions, but rather they disperse uniformly through the solution while retaining their molecular structure.
Thus, the correct statement describing what occurs when ionic compounds and polar molecules dissolve in water is: The ionic compound will dissociate, but the polar molecule will not.