Question

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correct answer=brainliest otherwise reported​

Answer 1

Answer:

The element has to be of group 15

The ionisation energy increases progressively from 1st to 3rd as a result of increase of effective nuclear charge ( charge due to which the nuclei binds the electrons ) but the 4th ionisation energy increases heavily . This is because the atom had lost all of its valence electrons and now it loses electron from its inner shell which resulted in a high 4th ionisation energy .

Chloride — MCl3

Oxide — M2O3