Transferring of electrons from a metal atom to a non-metal atom

Electrostatic attraction between positive metal ions and the negative delocalised electrons

Sharing of electrons between non-metallic atoms in Group IV, V, VI, VII

Valency: Number of valence electrons an atoms used to form the chemical bond

Solid state:Ions held in fixed positions by strong electrostatic forces of attraction within crystal lattice structure

Molten or Aqueous state: crystal lattice structure broken down, strong ionic bonds are overcomed enabling ions to move freely

It consists of positive metallic ions and negative non-metallic ions bonded strongly together in fixed position by strong ionic bonds in a crystal lattice structure. Large amount of energy is required to overcome the strong ionic bonds. Thus, it exists as solid at room temperature.

It has macromolecular structure. Each carbon is bonded tetrahedrally to 4 other carbon atoms. All atoms are bonded by strong covalent bonds to give a 3-dimensional rigid giant network. Large amount of energy is needed to overcome the strong covalent bonds.

It has a giant covalent structure. Each silicon atom is tetrahedrally bonded to 4 oxygen atoms and each oxygen atom is bonded to 2 silicon atoms by strong covalent bonds throughout the whole network structure.

It has a hexagonal layered structure. In each layer, there are rings of 6 carbon atoms joined together. Within the layer, each carbon atom is bonded to 3 other carbon atoms by strong covalent bonds. Between the layers, weak intermolecular forces exist. These forces can be overcomed with little amount of energy, thus layer of carbon atoms can slip over one another,