The five successive ionization energies of the element are 800, 2427, 3658, 25024 and 32824 kJ mol–l
respectively. The number of valence electrons is:
(A) 3 (B) 5 (C) 4 (D) 2
After 3 succesive ionisation there is large differnece in ionisation of 3rd and 4th ionisation energy it means after removing 3 electrons the element get stable or u can say that it attain noble gas comfiguration....therefore there are 3 electrons in valance shell