Lewis Beverage cup arrangement in the case of NH3 is illustrated by the valence electrons surrounding the N atom. The Lewis point arrangement in the case of NH3 reveals that the nitrogen atom unites 1 pair of e- with each of the three hydrogen atoms, resulting in a total of 3 united pairs of electrons. The ammonia molecule adopts a three-sided pyramid-like shape because of the placement of the outer electrons according to its Lewis dot structure. In the Lewis symbol representation of ammonia, the N atom is encircled by three dots, each representing a pair of united electrons with a H atom.