Electron pair Beverage cup structure in the case of NH3 is depicted by the outer electrons surrounding the N atom. The Lewis dot arrangement for ammonia unveils that the nitrogen atom unites 1 pair of electrons with each of the three H atoms, resulting in a overall of three joined 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 symbol depiction of ammonia, the N atom is enclosed by three dots, each representing a pair of connected electrons with a hydrogen atom.