Deep in the valley of the Periodic Table lived a large, charismatic atom named Sulfur. Sulfur was unique. Unlike his neighbor, the rigid Carbon, Sulfur had an expanded wardrobe—empty d-orbitals that allowed him to dress up in more than eight electrons. Today, Sulfur faced a dilemma. He had four Oxygen atoms asking for his attention. Each Oxygen needed two electrons to complete its own valence shell.
"No lone pairs to hide," Sulfur said. "What you see is what you get." so4 2 electron geometry and molecular geometry
Sulfur made a decision. He would use his d-orbital expansion. He promoted one of his 3s electrons to a higher energy level, creating six unpaired electrons. Then, he borrowed two extra electrons from the universe (giving the ion its ( 2- ) charge). Now, with eight electrons to allocate, he invited the four Oxygens to bond. Deep in the valley of the Periodic Table
Sulfur nodded. He arranged his four double bonds like the corners of a pyramid. Today, Sulfur faced a dilemma
"Four regions," whispered the ghost of Electron Geometry. "That means I must arrange you in . 109.5 degrees apart. This is the most comfortable way for four clouds to sleep in the same bed."