Here's why:

* Ionic bonds: Ionic compounds are formed by the electrostatic attraction between positively charged cations and negatively charged anions. These attractions are very strong, creating a rigid, crystalline structure.

* High melting points: To melt an ionic compound, you need to overcome these strong electrostatic forces. This requires a significant amount of energy, resulting in high melting points.

Let me know if you'd like more details on ionic bonding or the factors affecting melting points!