Why do ionic compounds have high melting points?

Ionic compounds are formed by the electrostatic attraction between positively and negatively charged ions, resulting in strong ionic bonds. These ionic bonds create a crystal lattice structure, which is a highly ordered and stable arrangement of ions. The strength of these ionic bonds determines the energy required to separate the ions in the lattice.

To melt an ionic compound, this crystal lattice must be broken apart, which requires substantial energy to overcome the strong electrostatic forces holding the ions together. This energy input is reflected in the high melting points of ionic compounds compared to covalent compounds or simple molecules.

In contrast, options that suggest the presence of small molecules or gases at room temperature do not accurately represent the nature of ionic compounds, as they typically exist as solid structures at room temperature. Additionally, stating that they require less energy to break apart underestimates the strength of the ionic bonds. Therefore, the strong ionic bonds confident in the increased energy requirement to break them effectively explains why ionic compounds have high melting points.