Table 1 displays experimental data on the physical properties of three different crystalline solids, D, E, and F.
| Substance | Melting point (∘C^\circ\text{C}∘C) | Electrical conductivity as a solid | Electrical conductivity when liquid / molten |
|---|---|---|---|
| D | 1414 | Poor | Poor |
| E | 714 | Poor | Good |
| F | 98 | Good | Good |
Deduce, using the information in Table 1, the structure and bonding of substances D, E and F. Explain the properties of each substance in terms of its structure and bonding.