Molecular Geometry of Ammonia (NH₃) - VSEPR Theory

What is the molecular geometry of Ammonia (NH₃)?

Ammonia (NH₃) has 4 electron domains around the central N atom: 3 bonding and 1 lone pair(s). The electron domain geometry is tetrahedral, giving a trigonal pyramidal molecular shape with bond angles of approximately 107 degrees.

FormulaNH₃
NameAmmonia
Central AtomN
Bonding Domains3
Lone Pair Domains1
Total Electron Domains4
Electron Domain GeometryTetrahedral
Molecular GeometryTrigonal Pyramidal
Bond Angle107°

Electron Domain Count

Nitrogen has 3 bonding domains (one for each N–H bond) and 1 lone pair = 4 total electron domains.

Electron Domain Geometry

4 electron domains arrange tetrahedrally, just like methane. The lone pair occupies one tetrahedral position.

Molecular Geometry

Remove the lone pair from the picture — the 3 remaining bonds form a trigonal pyramid. The nitrogen sits above the plane of the three hydrogens.

Bond Angle

The bond angle is 107° instead of 109.5°. The lone pair takes up more space than a bonding pair, slightly compressing the H–N–H angles.

See electron domains, molecular shapes, and bond angles on interactive 3D molecules with Lewis structure overlays.

Visualize Ammonia's Geometry in 3D

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