Why is ionization energy of oxygen less than nitrogen?

Oxygen has one paired 2p orbital; electron–electron repulsion makes removing one electron easier than from nitrogen's half-filled 2p³.

Review this question in context

This page is part of Why is ionization energy of oxygen less than nitrogen? on MCQCampus. Read the question carefully, choose an answer before checking the explanation, and use the related category, paper, job or exam-year links to understand where the question belongs in your wider preparation.

Build stronger recall

A useful revision method is to answer from memory first, then compare your choice with the correct answer and explanation. If the question is linked to more than one paper or job year, review those related pages as well because repeated concepts can be useful signals when planning revision.

Continue with related MCQs

Use the related links below to practise more questions from the same subject or exam path. Moving between a question, its category and its past-paper hierarchy creates a clearer study trail than practising isolated questions without context.