MDCAT Chemistry MCQ #847

Why does nitrogen exhibit a higher first ionization energy than oxygen despite oxygen having a greater effective nuclear charge?

MDCAT Chemistry MCQ #847

  1. Question 1

    Q1. Why does nitrogen exhibit a higher first ionization energy than oxygen despite oxygen having a greater effective nuclear charge?

    • A) Electron-electron repulsion in oxygen's 2p orbitals
    • B) Smaller atomic radius of nitrogen
    • C) Greater shielding effect in nitrogen
    • D) Higher nuclear charge in oxygen

    Answer: Electron-electron repulsion in oxygen's 2p orbitals

    Explanation: Oxygen's filled 2p orbitals cause repulsion, reducing ionization energy; nitrogen's half-filled orbitals are more stable.