So4 -2 Lewis Here

To the other two Oxygens, he gave single bonds but with a heavy heart: "You will carry the negative charge for the team."

Suddenly, a wise old floated by. "You have a secret power, Sulfur," it whispered. "You are in Period 3. You can expand your octet. Use your empty 3d orbitals ."

Every millisecond, the double bonds would hop from one Oxygen to another. Click. Now a different Oxygen has the double bond. Click. Now another. so4 -2 lewis

But there was a problem. When Sulfur tried to share a single pair of electrons with each Oxygen (making four single bonds), he ran out of electrons. He was left with a miserable +4 formal charge, and each Oxygen had a -1 charge. The structure was unstable, like a table with three legs.

"Let's bond!" said Sulfur. "I have six valence electrons of my own. You four each have six. Together, we can form a stable ring of eight." To the other two Oxygens, he gave single

But the Oxygen atoms were democratic. They didn't like that only two got the "honor" of a double bond. So they did something magical: .

Sulfur’s eyes lit up. "Of course!"

And so, ( \text{SO}_4^{2-} ) became the most stable, famous, and well-respected ion in the valley. It was the backbone of gypsum, Epsom salts, and bathtub relaxation.