Lewis Beverage cup structure in the case of ammonia is illustrated by the outer electrons surrounding the nitrogen atom. The Lewis dot structure for ammonia exhibits that the nitrogen atom joins 1 pair of e- with each of the three hydrogen atoms, resulting in a total of a trio shared pairs of electrons. The NH3 molecule takes a trigonal pyramidal shape due to the placement of the outer electrons according to its Electron pair dot arrangement. In the dot symbol depiction of ammonia, the N atom is surrounded by three dots, each representing a pair of shared electrons with a hydrogen atom.

Ammonia NIST Chemistry WebBook