MDCAT Chemistry MCQ #781

Why does gallium have a smaller atomic radius than aluminum?

MDCAT Chemistry MCQ #781

  1. Question 1

    Q1. Why does gallium have a smaller atomic radius than aluminum?

    • A) Poor d-orbital shielding in gallium
    • B) Higher period number for gallium
    • C) Lower nuclear charge in gallium
    • D) Greater electron-electron repulsion in gallium

    Answer: Poor d-orbital shielding in gallium

    Explanation: Gallium's d-electrons shield poorly, increasing effective nuclear charge. Higher period number (option B) would increase radius.