Q5(h). Magnetic moment: spin only in the d-block, not in the f-block
The magnetic moment of d-block elements arises mainly from the contribution of spin motion of the electrons but in case of f-block elements, it is not valid. Justify the statement.
Answer in brief
In 3d ions the ligand field quenches the orbital moment, so μ = √(n(n + 2)); in 4f ions the orbital moment survives and couples with spin, so μ = gJ√(J(J + 1)).
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Coversspin-only magnetic momentorbital quenchingRussell–Saunders couplinglanthanide magnetismLandé g factor
All parts of Question 5
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- 5(b) Light absorbed by a dye solution5 marks
- 5(c) Surface area of charcoal from a nitrogen monolayer5 marks
- 5(d) Showing that a decomposition is first order5 marks
- 5(e) Structure of [4Fe–4S] ferredoxin5 marks
- 5(f) Which complex has the larger Δₒ10 marks
- 5(g) Completing five p-block reactions10 marks
- 5(h) Magnetic moment: spin only in the d-block, not in the f-block5 marks