According to Valence Shell Electron Pair Repulsion (VSEPR) theory, what determines the geometry of a molecule?

• A. The atomic masses of the atoms in the molecule
• B. The total number of protons in the molecule
• C. The number of electron pairs (bonding and lone pairs) around the central atom
• D. The electronegativity difference between the atoms

Answer: (C)

Verified step by step guidance

1. Understand that VSEPR theory is used to predict the shape of a molecule based on the repulsions between electron pairs around the central atom.
2. Identify that the key factor in determining molecular geometry is the number of electron pairs (both bonding pairs and lone pairs) surrounding the central atom.
3. Recognize that these electron pairs repel each other and arrange themselves as far apart as possible to minimize repulsion, which dictates the molecular shape.
4. Note that atomic masses, total number of protons, or electronegativity differences do not directly determine the geometry according to VSEPR theory.
5. Conclude that the correct determinant of molecular geometry in VSEPR theory is the number of electron pairs around the central atom.