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CHM 101 CHM 101 Past Questions Objective Question
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Question

Arrange the following isoelectronic species in order of increasing length of their radii. Na⁺, Mg²⁺, F⁻, O²⁻.
Options
A Mg²⁺ < O²⁻ < F⁻ < Na⁺
B O²⁻ < F⁻ < Na⁺ < Mg²⁺
C F⁻ < O²⁻ < Mg²⁺ < Na⁺
D Mg²⁺ < Na⁺ < F⁻ < O²⁻
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

All species have 10 electrons. Ionic radius decreases with increasing nuclear charge (more protons pull electrons in tighter). Nuclear charges: Mg²⁺ (12), Na⁺ (11), F⁻ (9), O²⁻ (8). Therefore, order of increasing radius: Mg²⁺ < Na⁺ < F⁻ < O²⁻.

Hint

For isoelectronic species, the one with the greatest nuclear charge has the smallest radius.

Question Info

Course: CHM 101
Topic: CHM 101 Past Questions
Type: Objective
Difficulty: Not specified
Question 1688 of 1872
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