Which principle does VSEPR theory rely on to determine molecular geometry?

• A. Electron pairs around a central atom repel each other to minimize repulsion
• B. Bond energy determines geometry
• C. Electron pairs always occupy the same orbital
• D. Molecular shape is random

Answer: (A)

VSEPR theory is built on the idea that electron pairs around a central atom repel one another and spread out as far as possible to minimize repulsion. These electron domains, whether bonding pairs or lone pairs, define the arrangement of the atoms in space. The specific geometry that results is determined by how many electron domains surround the central atom, with lone pairs taking up more space and subtly altering bond angles. This is why molecules with a given number of electron domains have predictable shapes, and why lone pairs can bend bond angles away from the idealized forms—such as how water ends up with a bent shape due to two lone pairs. Bond energy tells you about bond strength, not how electron domains arrange themselves. Electron pairs do not always occupy the same orbital, and molecular shapes are not random; they follow these repulsion-driven arrangements to yield consistent geometries.