Physical Properties
Compare and explain the properties of substances resulting from different types of bonding
| Type of bonding | Ionic | Metallic | Covalent molecular | Covalent network lattice |
| Melting and boiling point | Very high | Medium to high | Low | Very high |
| Why | Packed closely in the lattice. Bond is strong and require a large amount of energy to break the bond | Depends on the size and charge of the ions. Metallic bonding is stronger than intermolecular forces | Weak bonds between molecules | Covalent bonds between all the atoms require large amounts of energy to break |
| Volatility | Low | Usually low (exception Mercury) | High | Low |
| Why | Solid at room temperature and have a high boiling point. Difficult to vaporise | Solid at room temperature, high boiling point.
Mercury is a liquid. |
Easy to break the weak intermolecular forces between molecules. | Usually solids at room temperature and high boiling points. |
| Electrical conductivity | Conduct when dissolved in water or in the liquid state | All conduct in the solid state | Polar molecules conduct when they are dissolved. Non- polar ones do not conduct at all | Graphite is the only one that will conduct electricity |
| Why | Only free to move in these conditions | Sea of delocalised electrons allow electrical current to be conducted | Polar molecules form ions when they dissolve | Delocalised electrons in graphite. Other do not have free particles or electrons |
| Solubility | Some will dissolve in a polar solvent, while others will not dissolve at all | Some metals react with water to make alkaline solutions, others will not dissolve at all | Polar molecules dissolve in polar substances, non- polar molecules dissolve in non- polar substances | Do not dissolve in any solvents |
| Why | The attraction to the solvent must be greater than the attraction to the other ions | Ones that react are excellent reducing agent, and undergo a redox reaction with water. The rest have bonds that are too strong for the water to break | Polar molecules are ionised as they dissolve. Non-polar molecules bond using Van der Waals’ forces | The covalent bonding is not influenced by the solvents |