Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code : Column I; Column II a. Co^3+; i. √(8) B.M. b. Cr^3+; ii. √(35) B.M. c. Fe^3+; iii. √(3) B.M. d. Ni^2+; iv. √(24) B.M. ; v. √(15) B.M.

NEET UG 2018 · Chemistry · Question 69

NEET 2018 Chemistry, question 69

Question 69 of the NEET 2018 paper (code AA) is a Chemistry question from The d- and f-Block Elements. Its idea, Magnetic Moment and Colour of d- and f-Block Ions, was asked 7 times, in 2018, 2020, 2024, 2025 and 2026, across NEET 2017–2026. The CBSE official answer key gives option 3.

Updated 2026-10-08

Q69 · Chemistry

\mathrm{Co^{3+}}

Column I	Column II
a. $\mathrm{Co^{3+}}$	i. $\sqrt{8}$ B.M.
b. $\mathrm{Cr^{3+}}$	ii. $\sqrt{35}$ B.M.
c. $\mathrm{Fe^{3+}}$	iii. $\sqrt{3}$ B.M.
d. $\mathrm{Ni^{2+}}$	iv. $\sqrt{24}$ B.M.
	v. $\sqrt{15}$ B.M.

1 a-iv, b-i, c-ii, d-iii 2 a-i, b-ii, c-iii, d-iv 3 a-iv, b-v, c-ii, d-i Official answer 4 a-iii, b-v, c-i, d-ii

Official answer: option 3 · CBSE official answer key

Same idea

Magnetic Moment and Colour of d- and f-Block Ions, in other papers

NEET asked this idea 7 times, in 2018, 2020, 2024, 2025 and 2026. The other 6 questions below.

^{3+}

Magnetic Moment and Colour of d- and f-Block Ions: every question and how it was framed

The chapter

The d- and f-Block Elements in ten years of NEET

21 questions from 2017–2026, asked in 10 of 10 papers, about 2.0 a paper. d- and f-Block Elements alone had 21.

Chapter analysis Study this chapter Practise this chapter

Magnetic Moment and Colour of d- and f-Block Ions, in other papers

The d- and f-Block Elements in ten years of NEET

The d- and f-Block Elements: questions per paper