The four main categories of crystals are grouped based on their chemical and physical properties. Covalent crystals have covalent bonds between all the atoms in the crystal and because there are no delocalized electrons, they do not conduct electricity. A covalent crystal can be thought of as one big molecule. Most covalent crystals have extremely high melting points. This is due to the breaking of covalent bonds requiring large amounts of energy. Covalent bonds in general are extremely strong so covalent solids are quite hard. This makes the crystals insoluble due to the difficulty of solvating very large molecules. Some examples of covalent crystals include diamond and zinc sulphide crystals.
The four main categories of crystals are grouped based on their chemical and physical properties. Covalent crystals have covalent bonds between all the atoms in the crystal and because there are no delocalized electrons, they do not conduct electricity. A covalent crystal can be thought of as one big molecule. Most covalent crystals have extremely high melting points. This is due to the breaking of covalent bonds requiring large amounts of energy. Covalent bonds in general are extremely strong so covalent solids are quite hard. This makes the crystals insoluble due to the difficulty of solvating very large molecules. Some examples of covalent crystals include diamond and zinc sulphide crystals.