Electron pair dot arrangement in the case of ammonia is a representation of the outer electrons surrounding the N atom. The dot dot arrangement in the case of NH3 displays that the nitrogen atom joins one pair of e- with each of the three H atoms, resulting in a total of a trio joined pairs of electrons. The NH3 molecule adopts a trigonal pyramidal shape because of the arrangement of the valence electrons according to its Lewis dot structure. In the Lewis dotpoint representation of ammonia, the nitrogen atom is enveloped by three dots, each representing a pair of joined electrons with a hydrogen atom.