Concept:Generally, Ionization Energy (IE) increases across a period from left to right due to an increase in effective nuclear charge, which holds valence electrons more tightly.
Solution:- The given elements belong to the 2nd period. Their increasing order of atomic number is: B (5), C (6), N (7), Ne (10).
- Following the general trend, IE increases across the period.
- Therefore, the standard expected order is: B < C < N < Ne.
- Note: While Nitrogen has a slightly anomalously high IE compared to Oxygen due to a half-filled p-orbital, Oxygen is not listed in the options, so the standard trend holds perfectly for the given elements.
Why other options are incorrect:- Option A, C, and D provide incorrect sequences that contradict the increasing effective nuclear charge trend across the period.
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