According to Valence Shell Electron Pair Repulsion (VSEPR) theory, how does the arrangement of electron pairs around a central atom affect the shape of a molecule?

• A. VSEPR theory states that all molecules have a tetrahedral shape regardless of electron pair arrangement.
• B. Electron pairs attract each other and cluster closely around the central atom, resulting in a linear shape.
• C. Electron pairs repel each other and arrange themselves as far apart as possible, determining the molecular geometry.
• D. The shape of a molecule is determined only by the number of atoms bonded to the central atom, not by electron pairs.

Answer: (C)

Verified step by step guidance

1. Understand that VSEPR theory is based on the idea that electron pairs around a central atom repel each other because they have negative charges.
2. Recognize that these repulsions cause electron pairs to arrange themselves in a way that minimizes repulsion, meaning they spread out as far apart as possible around the central atom.
3. Know that both bonding electron pairs (shared between atoms) and lone pairs (non-bonding pairs) influence the shape of the molecule because they occupy space and repel each other.
4. Realize that the arrangement of these electron pairs determines the molecular geometry, which can be linear, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral, etc., depending on the number of electron pairs and their positions.
5. Conclude that the molecular shape is not fixed as tetrahedral for all molecules, nor is it determined solely by the number of bonded atoms; instead, it depends on the repulsions between all electron pairs around the central atom.