If you understand NaCl you can apply this knowledge to any ionic bond. A key idea is when valence electrons are transferred, positive and negative ions are formed. These ions are attracted and make the ionic bond.
Ionic compounds are made up of positive (cations) and negative ions (anions). You can find the ionic charge of these ions using the Periodic Table. Many properties can be explained due to the electrostatic nature of ionic bonds.
| Property | Ionic Bonds | Covalent Bonds |
|---|---|---|
| State | crystalline solids | solids, liquids, gases |
| Melting and Boiling point | High | Low |
| Solubility | Usually dissolves in water but not in non-polar liquids. | Usually soluble in non-polar liquids but not in water. |
| Conductivity | Conducts electricity when melted or dissolved in water. | Does not conduct electricity. |
| Hardness | Hard and brittle | For covalent solids - usually soft |