Why do ionic compounds have high melting and boiling points?

Ionic compounds have high melting and boiling points due to the strong electrostatic forces between their positive and negative ions.

Ionic compounds are formed when a metal reacts with a non-metal. They consist of positive and negative ions which are held together by strong electrostatic forces of attraction, known as ionic bonds. These bonds form a giant ionic lattice structure, which is a repeating pattern of ions. This structure is extremely stable due to the strong attraction between the oppositely charged ions.

The high melting and boiling points of ionic compounds are a direct result of these strong ionic bonds. In order to melt or boil an ionic compound, a significant amount of energy is required to overcome these forces of attraction and break the bonds. This is why ionic compounds are often solid at room temperature and require high temperatures to change their state.

For example, common table salt (sodium chloride) is an ionic compound. It has a melting point of 801 degrees Celsius and a boiling point of 1,413 degrees Celsius. This is because the sodium ions (Na+) and chloride ions (Cl-) are strongly attracted to each other, forming a stable lattice structure that requires a large amount of energy to break apart.

In summary, the high melting and boiling points of ionic compounds are due to the strong electrostatic forces between their positive and negative ions. These forces create a stable lattice structure that requires a significant amount of energy to disrupt, resulting in high melting and boiling points.