Correction: No. The angles are all approximately 109.5° . It is not based on octahedral or trigonal planar parent geometries.
Correction: No. This is the most persistent error in student drawings. All four S–O bonds are identical in length, strength, and chemical behavior. The correct representation is a resonance hybrid with a circle or dashed lines inside the tetrahedron, or simply acknowledging the equal bonds. so42 molecular geometry
If you draw the Lewis structure for sulfate using simple rules, you might draw two single bonds and two double bonds. But this presents a problem: if the bonds were truly different (some single, some double), the lengths of those bonds would be different. A double bond is shorter and tighter than a long, loose single bond. Consequently, the geometry would be distorted; the tetrahedron would be lopsided. Correction: No
Imagine a tripod with three legs on the ground and a camera pointing up; now, imagine adding a fourth leg pointing straight down. That is the essence of the tetrahedron. The bond angles between the oxygen atoms are ideally 109.5 degrees. This shape allows the oxygen atoms to maximize their distance from one another, creating a structure of supreme stability. It is a geometric "sweet spot" that minimizes internal stress. The correct representation is a resonance hybrid with
Even though we draw single and double bonds, resonance causes all four S-O bonds to be the same length—somewhere between a single and double bond. 4. Hybridization
Correction: While the expanded octet model uses d orbitals for π bonding, the electron count in the valence shell is effectively 12 if you count both σ and π electrons. However, modern computational chemistry shows that the d orbital contribution is small; the bonding is better described as highly delocalized, with sulfur carrying a significant partial positive charge. But for introductory purposes, "expanded octet" is a useful heuristic.
Theory is beautiful, but experiments confirm reality.