The electron cloud geometry of NH3 (ammonia) is tetrahedral. This is because the central nitrogen atom has four regions of electron density: three bonding pairs of electrons (each forming a bond with a hydrogen atom) and one lone pair of electrons.
However, the molecular shape of NH3 is trigonal pyramidal. This is due to the presence of the lone pair of electrons on the nitrogen atom, which repels the bonding pairs slightly more than they repel each other. As a result, the hydrogen atoms are pushed down, creating a pyramidal shape.
In summary:
- Electron Cloud Geometry: Tetrahedral
- Molecular Shape: Trigonal Pyramidal