All the three elements belong to the same group in the periodic table, that is Group 15 (Va) of the periodic table. They are also known as Nitrogen group element, others are, antimony, bismuth and moscovium. They share certain general similarities in chemical behavior, which reflect common features of the electronic structures of their atoms.
Each element occupies the fifth position among the main group elements of its period, a position designated 15. Also they possess an outermost shell of five electrons. Additionally, they have an unshared, or lone pair of electrons which remains after the three covalent bonds, or their equivalent, have been formed.