In a Lewis dot structure, valence electrons of an atom are represented by dots placed around the chemical symbol of the element. The number of dots represents the number of valence electrons the atom has.
- Each single dot represents one valence electron.
For example, the Lewis dot structure of hydrogen (H) has one dot, which represents its single valence electron:
```
H
```
- When there is a pair of valence electrons that occupy a molecular orbital they are represented as a pair of dots.
The Lewis dot structure of oxygen (O) has six dots, representing its six valence electrons:
```
:
O :
:
```
- When the atom loses the valence electrons, the lost valence electrons are represented as a hole.
- Valence electrons of bonded atoms are often shown as lines connecting atoms, which illustrate shared pairs of electrons.
For example, the Lewis dot structure of hydrogen molecule (H2) shows two dots between two hydrogen atoms, which signifies the sharing of two valence electrons:
```
H : H
```
- Similarly, the Lewis dot structure of water molecule (H2O) shows two dots between each oxygen and hydrogen atoms signifying twoshared pairs of electrons between them:
```
H H
| |
O
```
