1. Count the total valence electrons:
* Carbon (C) has 4 valence electrons each, so 2 C atoms contribute 2 * 4 = 8 electrons.
* Hydrogen (H) has 1 valence electron each, so 2 H atoms contribute 2 * 1 = 2 electrons.
* Total valence electrons: 8 + 2 = 10
2. Determine the central atom:
* Carbon is less electronegative than hydrogen, so it will be the central atom.
3. Connect the atoms with single bonds:
* Place the two carbon atoms next to each other, and connect each carbon atom to a hydrogen atom with a single bond.
4. Complete the octets around the atoms (except hydrogen):
* Each carbon atom currently has only 3 electrons. To achieve an octet, each carbon atom needs to form a triple bond with the other carbon atom. This uses up the remaining 4 valence electrons.
5. The final Lewis structure:
* The final Lewis structure of C₂H₂ has a triple bond between the two carbon atoms and a single bond between each carbon and a hydrogen atom.
Here's the representation:
```
H
|
H - C ≡ C - H
```
Key features of the structure:
* Each carbon atom has a full octet (8 electrons).
* Each hydrogen atom has 2 electrons (a duet).
* The molecule is linear.
* The triple bond between the carbon atoms is very strong and gives acetylene its unique properties.
