MDCAT Chemistry MCQ #1728

A chemistry student observes that atomic radius decreases from Sodium to Argon in the third period. What is the primary cause of this periodic trend?

MDCAT Chemistry MCQ #1728

  1. Question 1

    Q1. A chemistry student observes that atomic radius decreases from Sodium to Argon in the third period. What is the primary cause of this periodic trend?

    • A) Increase in shielding effect
    • B) Increase in nuclear charge
    • C) Decrease in number of shells
    • D) Increase in atomic mass

    Answer: Increase in nuclear charge

    Explanation: Radius decreases because nuclear charge increases while shielding remains constant. Option A fails as shielding does not increase across a period.