how is ionic crystal formed
In summary, a crystal is any solid material with its atoms organized in a repeating pattern. There are four types of crystals. Covalent crystals occur when the atoms form strong, covalent bonds. Such crystals, like diamonds, are very tough. Ionic crystals, like table salt, are hard and stable but are made of atoms connected by electrical charges. Metallic crystals are formed from metal elements and conduct electricity well. Molecular crystals, like rock candy, are formed through hydrogen bonds and are generally weak and have a low melting point.