What characteristic defines distilled water?

The defining characteristic of distilled water is that it is devoid of other substances. Distillation is a process that involves boiling water to produce steam and then cooling the steam back into liquid form. This process effectively removes impurities, minerals, contaminants, and other dissolved substances, resulting in water that is pure and free from anything except H2O.

In comparison to distilled water, options such as containing minerals or being treated with chlorine do not apply, as the distillation process specifically aims to eliminate such additives. High pH is also not relevant, as distilled water typically has a neutral pH around 7, which means it is not high in pH. Thus, the purity of distilled water, marked by its lack of additional substances, makes the correct choice clear.