Valence electrons are not responsible for A. B. O D. The chemical reactivity of an atom The bo atom The characteristics of an anion or cation The electron affinity of an atom nding characteristics of an E. Why atoms are in the same group on the periodic table Solution Answer is :- C. The characteristics of an anion or cation. The valence electron is mainly responsibe for chemical reaction they involved in the electron transfer and electron acceptor to produce the new molecule. Then the bonding nature of the atom mainly depends on the number of valence electron if it has three elctron then atom having the abilitity to form triple bond. The valence electrons does not provide any idealogy of the charecteristics of the cation and an ion like when it react and or not. Then valence elctron is responsible of the electron affinity and group to place element. same numer of valence electronic atoms are placed in the same group. .