Which of the following best explains why ionic compounds have high melting and boiling points?

• A. They contain hydrogen bonds, which are the strongest type of intermolecular force.
• B. Their atoms are bonded by covalent bonds, which require little energy to break.
• C. They are held together by strong electrostatic attractions between oppositely charged ions.
• D. They consist of molecules held together by weak London dispersion forces.

Answer: (C)

Verified step by step guidance

1. Understand that melting and boiling points depend on the strength of the forces holding particles together in a substance.
2. Recall that ionic compounds are composed of positively and negatively charged ions arranged in a lattice structure.
3. Recognize that the forces between these ions are strong electrostatic attractions, also known as ionic bonds.
4. Compare these ionic bonds to other types of intermolecular forces such as hydrogen bonds, covalent bonds, and London dispersion forces, noting that ionic bonds are generally stronger than these forces.
5. Conclude that the high melting and boiling points of ionic compounds are due to the strong electrostatic attractions between oppositely charged ions, which require a large amount of energy to overcome.