The first ionization enthalpies of Be, B, N and O follow the order
Solution
The first ionization energy increase from left to right along $2^{\text {nd }}$ period with the following exceptions
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$\mathrm{IE}_{1}: \mathrm{Be}>\mathrm{B}$ and $\mathrm{N}>\mathrm{O}$
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This is due to stable configuration of $\mathrm{Be}$ in comparison to $\mathrm{B}$ and that of $\mathrm{N}$ in comparison to $\mathrm{O}$.
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Hence the correct order is $\mathrm{N}>\mathrm{O}>\mathrm{Be}>\mathrm{B}$
About this question
Subject: Chemistry · Chapter: Periodic Table and Periodicity · Topic: Periodic Trends
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