Properties of Substances
- Elements can form different types of substance:
- The type of structure formed gives rise to bulk properties
- Examples of bulk properties include electrical conductivity, and melting/boiling points
- Individual atoms do not possess these physical properties, rather they arise due to many atoms, ions or molecules acting together
Summary of the properties of different substances
| Type of substance | Example | Can it conduct? | Explanation | Melting / boiling point | Explanation |
| Ionic | sodium chloride |
No when solid Yes when molten or aqueous |
When molten or aqueous, the ions are free to move and carry a charge | High | Strong electrostatic forces of attraction between oppositely charged ions |
| Simple molecules | carbon dioxide | No | There are no free charged particles | Low | Weak intermolecular forces |
| Giant covalent | graphite, diamond | No (except graphite and fullerenes) | Graphite and fullerenes have delocalised electrons which are free to move and carry a charge | High | Strong covalent bonds between atoms |
| Metallic | copper, sodium | Yes | Delocalised electrons which are free to move and carry a charge | High | Strong attraction between metal ions and delocalised electrons |
Exam Tip
It is important that you can explain the properties of each type of substance which can be found in detail in the next few pages.
