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JEE Main 2017 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 2 April 2017 (offline), Chemistry Q45

Question 45 of 90 in this shift, Chemistry question 15 of 30.

The group having isoelectronic species is :

(1) $\mathrm{O^{2-}, F^-, Na, Mg^{2+}}$
(2) $\mathrm{O^-, F^-, Na^+, Mg^{2+}}$
(3) $\mathrm{O^{2-}, F^-, Na^+, Mg^{2+}}$ Official answer
(4) $\mathrm{O^-, F^-, Na, Mg^+}$

Official answer

Option 3

CBSE answer key (25/04/2017, used for result).

Chapter: Classification of Elements and Periodicity in Properties
Topic: Quantum Numbers
Idea tested: Configurations of Isoelectronic Species

Same idea in other shifts

Asked 2× in all

28 Jul 2022, Shift 2 · Q38Which of the following pair is not isoelectronic species? (At. no. Sm, 62; Er, 68; Yb, 70; Lu, 71; Eu, 63; Tb, 65; Tm, 69)MediumSingle correct

Question text from the official JEE Main paper published by NTA (CBSE ran the 2017 exam); answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.