Yet ammonia's measured H-N-H angle is a little under 109.5 degrees. The reason is that a lone pair:
ACarries no charge
BAttracts protons
CWeighs much more
DTakes more room
Answer & Solution
Correct answer: D. Takes more room
1. A lone pair is held by one nucleus only, not shared between two.
2. Being less confined, it spreads into a fatter region and pushes harder.
3. Taking more room, it squeezes the bonding pairs and shrinks the angle.
_Source: OpenStax Chemistry 2e, Chapter 7, Chemical Bonding and Molecular Geometry._
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