What is the key characteristic of strong acids?

The key characteristic of strong acids is that they ionize completely in water, resulting in a high concentration of hydrogen ions (H⁺). This ionization is reflected in their pH, which typically ranges close to 0. A strong acid's ability to dissociate entirely means that even a dilute solution can have a very low pH value, indicative of its strength and reactivity.

In contrast, a pH greater than 7 indicates a basic or alkaline solution, which would not be characteristic of an acid. While strong acids do indeed neutralize bases effectively, this alone does not define their strength. Although strong acids may dissolve in water quickly, the speed of dissolution is not what delineates them from weaker acids. The definitive factor remains their complete ionization in solution and the resultant pH, which is typically near 0 for strong acids.