STUDENT SPACE · TOPIC 6
Ionic and molecular properties
Use structure, attractions and mobile charged particles to explain properties.
The essentials
- Ionic lattices have high melting points because much energy is needed to overcome strong electrostatic attractions.
- Ionic substances conduct when molten or dissolved because their ions can move. Solid ions stay in fixed positions.
- Simple molecular substances usually have low melting and boiling points because intermolecular forces are weak. Melting does not break their covalent bonds.
Key vocabulary
| English | Chinese |
|---|---|
| intermolecular force | 分子间作用力 |
| molten | 熔融的 |
| mobile ion | 可移动离子 |
Quick practice
Which charged particles carry current in molten sodium chloride?
Need a hint?
Ionic conduction involves movement of ions.
Check your reasoning after trying
Mobile sodium and chloride ions.
Use the matching chapter worksheet. Attempt independently, compare your reasoning with your partner, then bring unresolved questions to your teacher.