Recap all GCSE work covered about bonding, structure and properties.
Ionic bonding, including getting the right formula of a compound based on the ions it will form.
Covalent bonding, draw accurate diagrams of sharing electrons and introduce the idea of the dative covalent bond using an arrow.
Metallic bonding – simple but important to understand
Look at all of the structure types – all ionic, metallic, covalent and giant covalent. Diamond, graphite, iodine, ice, iron, sodium chloride.
Shapes: learn all of the shapes and how to determine them. Once you have that, incorporate lone pairs as well as bonding pairs so that you can work out bond angles (where lone pairs are more repulsive than bonding pairs) and shapes as they do not include the bonding pair.
Electronegativity and Pauling’s scale. Learn the definition of electronegativity and ensure that you can identify polar molecules, don’t fall into the trap of not noticing when electronegative elements cancel each other out as in CO2.
Using the above, you can determine the types of intermolecular forces between molecules:
- Van der Waals’ forces – occur between all atoms and molecules. They are proportional to the number of electrons, this is why Br2 has a higher milting point than Cl2. These are the weakest forces of them all.
- Dipole interactions – these are present when a molecule is polar, these are the second strongest force and they occur whenever there is a dipole moment.
- Hydrogen bonding – the strongest of all of the intermolecular forces. These occur when hydrogen is attached to a nitrogen, an oxygen or a fluorine (NOF).