The table shows some properties of diamond and of two other solids.
Table: The melting point, hardness and electrical conductivity of diamond and of two other solids
| Substance | Melting point in ∘C^\circ\text{C}∘C | Hardness | Conducts electricity when solid |
|---|---|---|---|
| Diamond | 3550 | very hard | no |
| Substance X | 801 | brittle | no |
| Substance Y | 1085 | soft | yes |
Substance X is an ionic compound. Substance Y is a metal.
Use the table and your knowledge of structure and bonding to explain why diamond has a higher melting point than substance Y.
Diamond and substance X both fail to conduct electricity when solid. Explain why, for each substance.
Suggest why diamond is used for the cutting edge of a saw blade but substance Y is not.
40 exam-style questions on AQA GCSE Chemistry 2.3 Structure and bonding of carbon, covering 2.3.1 Diamond, 2.3.2 Graphite, and 2.3.3 Graphene and fullerenes. Each one has a worked solution and a mark scheme showing where the marks go.