1. Lewis Structure:
* Sulfur (S) has 6 valence electrons.
* Oxygen (O) has 6 valence electrons.
* Total valence electrons in SO₂ = 6 + (2 x 6) = 18
* Draw the Lewis structure:
* Place the sulfur in the center.
* Place the oxygens around the sulfur.
* Connect each oxygen to sulfur with a single bond (2 electrons shared).
* Complete the octets of the oxygens by adding lone pairs (6 electrons each).
You'll notice that sulfur now has 10 electrons around it (2 from the bonds and 6 from lone pairs). This is more than the usual 8 electrons for an octet.
2. Expanded Valence:
* Sulfur is in the third period of the periodic table.
* Third-period elements and beyond *can* have more than 8 electrons in their valence shell, due to the availability of d-orbitals. This is called an expanded valence.
3. Conclusion:
The expanded valence shell of sulfur in SO₂ has 10 electrons.
