1. Determine the number of valence electrons:
* Oxygen has 6 valence electrons.
* The 2- charge means there are 2 additional electrons.
* Total valence electrons: 6 + 2 = 8
2. Place the symbol for the element:
* Write the symbol "O" in the center.
3. Distribute the electrons:
* Place two dots on each side of the oxygen symbol.
* This represents the 8 valence electrons.
4. Indicate the charge:
* Place the charge "2-" in the upper right corner of the symbol.
The Lewis dot structure for the oxide ion (O²⁻) is:
```
..
:O:
..
2-
```
Important Note: The oxide ion is a dianion, meaning it has a -2 charge. This is because it has gained two extra electrons to complete its octet.
