According to VSEPR theory, the shape of a molecule is decided by
- A. the mutual repulsion of the electron pairs around the central atom, which arrange themselves as far apart as possible
- B. the masses of the atoms attached
- C. the number of neutrons in the central atom
- D. the temperature at which the molecule is examined
Explanation
Bonding and lone pairs are regions of negative charge, so they repel and settle into the arrangement of minimum repulsion, which fixes the geometry. Repulsion is strongest between two lone pairs, weaker between a lone pair and a bond pair and weakest between two bond pairs, and this order explains why bond angles are squeezed when lone pairs are present. Atomic mass plays no part.
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