Which property of ionic compounds results in their high melting and boiling points?

Ionic compounds exhibit high melting and boiling points primarily due to the presence of strong ionic bonds between the ions. In these compounds, ions are held together by the electrostatic forces of attraction that occur between positively charged cations and negatively charged anions. This attraction is very strong, requiring a significant amount of energy to overcome in order to separate the ions and transition the substance from solid to liquid or from liquid to gas.

In contrast, the options mentioning weak bonds or other types of bonds, such as covalent or intermolecular forces, do not accurately describe the nature of bonds present in ionic compounds. Weak bonds or strong covalent bonds do not contribute to the high melting and boiling points observed in ionic substances, as they are fundamentally different from the bonds formed in ionic lattices. Consequently, the strong ionic bonds are the reason for the substantial energy requirement to change the state of ionic compounds, resulting in their high melting and boiling points.