Which of the following is a property of an ionic compound?

• A. They are usually malleable.
• B. They are composed of molecules.
• C. They conduct electricity in solid state.
• D. They have high melting points.

Answer: (D)

Verified step by step guidance

1. Understand what ionic compounds are: Ionic compounds are formed by the electrostatic attraction between positively charged cations and negatively charged anions, creating a crystal lattice structure.
2. Recall the physical properties of ionic compounds: They typically have high melting and boiling points due to the strong ionic bonds holding the lattice together.
3. Consider electrical conductivity: Ionic compounds do not conduct electricity in the solid state because the ions are fixed in place within the lattice and cannot move freely.
4. Evaluate malleability and molecular composition: Ionic compounds are generally brittle (not malleable) and are composed of ions arranged in a lattice, not discrete molecules.
5. Conclude that the correct property of ionic compounds from the options given is that they have high melting points, reflecting the strong ionic bonds in their structure.