Home › JEE Advanced › Chemistry › Chemical Bonding ›  Using VSEPR theory, what is the molecular geometry of $\mathrm{NH_3}$ (three bond pairs and one lone pair on N)?
ATrigonal pyramidal
BTrigonal planar
CTetrahedral
DBent
Answer & Solution
Correct answer: A. Trigonal pyramidal
The electron-pair geometry around N is tetrahedral (four electron domains). The lone pair occupies one of those positions but is invisible when we describe the molecular shape. Looking at where the three H atoms actually sit relative to N, the molecule is trigonal pyramidal. The bond angle is about $107°$, slightly less than tetrahedral because the lone pair compresses the H–N–H angles.
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