Electron pair Beverage cup structure in the case of NH3 is a representation of the valence electrons surrounding the N atom. The dot point arrangement for NH3 reveals that the nitrogen atom shares one pair of e- with each of the three H atoms, resulting in a total of 3 connected pairs of electrons. The NH3 molecule takes a trigonal pyramidal form because of the arrangement of the valence electrons according to its Lewis Beverage cup arrangement. In the Lewis symbol representation of NH3, the nitrogen atom is enveloped by three dots, each representing a pair of shared electrons with a hydrogen atom.