question_answer

The successive ionisation energy values for an element X are given below

(i) \[{{1}^{st}}ionisation energy = 410 kJ mo{{l}^{-}}^{1}\]

(ii) \[{{2}^{nd}}ionisation energy = 820 kJ mo{{l}^{-}}^{1}\]

(iii) \[{{3}^{rd}}\,ionisation energy = 1100 kJ mo{{l}^{-}}^{1}\]

(iv) \[{{4}^{th}}\,ionisation energy = 1500 kJ mo{{l}^{-}}^{1}\]

(v) \[{{5}^{th}}ionisation energy = 3200 kJ mo{{l}^{-}}^{1}\]

What are the number of valence electron for the atom X?

Answer:

(4)