What is a defining characteristic of an ionic compound?

A defining characteristic of an ionic compound is that it conducts electricity when dissolved in a solution. Ionic compounds are composed of positively charged cations and negatively charged anions held together by strong electrostatic forces, known as ionic bonds. When these compounds are dissolved in water, they dissociate into their respective ions. The presence of these freely moving ions in solution allows the substance to conduct electricity, which is a key property of ionic compounds.

In contrast, the other options do not accurately describe ionic compounds. While they may include compounds with particular properties, they do not capture the essential nature of ionic compounds. For instance, ionic compounds typically consist of both metals and nonmetals, which is contrary to the notion that they are composed solely of non-metals. Additionally, ionic compounds usually have high melting and boiling points due to the strength of the ionic bonds, differing from the claim of having low melting points. Lastly, all ionic compounds contain cations, meaning that stating they do not contain any cations is fundamentally incorrect.