Lewis Structure Generator
Phosphine · PH3

PH3 Lewis Structure

Phosphorus forms three P–H single bonds and retains one lone pair. Four electron domains surround phosphorus, giving a trigonal pyramidal molecular shape.

Open PH3 in the generatorSee drawing steps
PH₃
:P: / | \ H H H
One lone pair on phosphorus
Total valence electrons8
Central lone pairs1
Electron geometryTetrahedral
Molecular geometryTrigonal pyramidal

PH3 overview

Phosphorus contributes five electrons and the hydrogens contribute three. Three bonds use six electrons, leaving one lone pair on phosphorus.

How to draw PH3

  1. Count 8 valence electrons.
  2. Place phosphorus in the center.
  3. Draw three P–H single bonds.
  4. Place the remaining pair on phosphorus.
  5. Verify zero formal charges and an AX3E arrangement.

Geometry and angle

PH₃ is trigonal pyramidal with a stored reference angle near 93.5°. Simple hybridization labels are classroom models and do not fully describe the bonding in heavier group-15 hydrides.

Common mistakes

  • Forgetting the phosphorus lone pair.
  • Calling PH₃ trigonal planar.
  • Adding lone pairs to hydrogen.
  • Using P=H multiple bonds.

Last reviewed: July 16, 2026. Educational reference only.