Lewis dot arrangement in the case of ammonia is shown
by the outer electrons surrounding the nitrogen atom.
The Lewis dot structure for ammonia displays that the N atom unites one pair of e- with each of the three hydrogen atoms, resulting in a complete of a trio connected pairs of electrons.
The NH3 molecule takes a trigonal pyramidal shape due to the arrangement of the outer electrons according to its Electron pair dot structure.
In the Lewis dotpoint representation of NH3, the nitrogen atom is surrounded by three spots, each representing a pair of shared electrons with a H atom.
