Which statement best describes a strong electrolyte?

A strong electrolyte is characterized by its ability to completely dissociate into ions when dissolved in water, resulting in a high concentration of free-moving ions in solution. These ions are responsible for conducting electricity efficiently, which is a hallmark of strong electrolytes. In contrast, substances that do not dissolve in water or do not dissociate completely, such as weak electrolytes, do not contribute significantly to conductivity. This solidifies the idea that a strong electrolyte, by virtue of its complete dissociation, leads to a substantial presence of ions, making it a good conductor of electricity.

High viscosity, poor conductivity, and insolubility in water are properties that do not align with the behavior of strong electrolytes. Therefore, the correct statement about a strong electrolyte is that it has a high concentration of ions in solution.