STUDENT SPACE · TOPIC 4
Covalent bonds
Use shared electron pairs to draw simple covalent molecules.
The essentials
- A covalent bond is a shared pair of electrons between two atoms.
- In the simple molecules here, hydrogen forms one bond, oxygen two, nitrogen three and carbon four.
- A dot-and-cross diagram shows bonding pairs and lone pairs. Check two electrons around H and eight around the other atoms in these examples.
Key vocabulary
| English | Chinese |
|---|---|
| covalent bond | 共价键 |
| shared pair | 共用电子对 |
| lone pair | 孤电子对 |
Quick practice
What does one line in a displayed formula represent?
Need a hint?
A line represents a pair, not a single electron.
Check your reasoning after trying
One covalent bond: one shared pair of electrons.
Use the matching chapter worksheet. Attempt independently, compare your reasoning with your partner, then bring unresolved questions to your teacher.