Please enable JavaScript.

Coggle requires JavaScript to display documents.

Chemistry: Bonding (Ionic Bonding (Desription (Ionic bonding form between…

- - - - This example shows the ionic bond of sodium chloride. The sodium atom loses an electron to the chloride atom to make sodium chloride where the sodium is positive and the chloride is negative.
  - - - The oppositely charged ions are arranged in a regular way to form giant ionic lattices. Ionic compounds often form crystals as a result.
- - - - Very high melting points - Substances with giant covalent structures have very high melting points, because a lot of strong covalent bonds must be broken. Graphite, for example, has a melting point of more than 3,600ºC.
        
        Variable conductivity - Diamond does not conduct electricity. Graphite contains free electrons, so it does conduct electricity. Silicon is semi-conductive - that is, midway between non-conductive and conductive.
    - - Giant covalent structures contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds. The atoms are usually arranged into giant regular lattices - extremely strong structures because of the many bonds involved.
    - - Graphite
        Graphite is a form of carbon in which the carbon atoms form layers. These layers can slide over each other, so graphite is much softer than diamond. It is used in pencils and as a lubricant. Each carbon atom in a layer is joined to only three other carbon atoms.
        
        Diamond
        Diamond is a form of carbon in which each carbon atom is joined to four other carbon atoms, forming a giant covalent structure.
        
        Silica, which is found in sand, has a similar structure to diamond. It is also hard and has a high melting point, but contains silicon and oxygen atoms, instead of carbon atoms.
        
        Graphite
        
        Diamond
        
        Silica
  - - - Low melting and boiling points - This is because the weak intermolecular forces break down easily.
        
        Non-conductive - Substances with a simple molecular structure do not conduct electricity. This is because they do not have any free electrons or an overall electric charge.
    - - An example is carbon dioxide (CO2), the molecules of which contain one atom of carbon bonded with two atoms of oxygen.
    - - Very strong van der waals forces but weak inter-molecular forces which hold them together.
- - - - The positive metal ions are surrounded by a sea of delocalised electrons. It is arranged in a giant lattice. The layers are weak as the electrostatic, intermolecular and Van Der Waals forces are weak.