Answer: 5.92 BM (n=5 unpaired electrons).
- A 5.92 BM (n=5 unpaired electrons)
- B 3.87 BM, the value corresponding instead to three unpaired electrons
- C 1.73 BM, the value corresponding instead to a single unpaired electron
- D 2.83 BM, the value corresponding instead to two unpaired electrons
Correct answer: A. 5.92 BM (n=5 unpaired electrons)
Explanation: Fe<sup>3+</sup> has d<sup>5</sup> high-spin configuration with 5 unpaired electrons: mu = sqrt(5×7) = sqrt(35) = 5.92 BM.
Aqueous solutions of transition metal ions show characteristic colours caused by electrons absorbing visible light to jump between split d-orbitals; the exact colour depends on the metal, its oxidation state, and surrounding ligands.
Concept context
Transition metals (d-block) and lanthanides/actinides (f-block). Known for coloured compounds, variable oxidation states, complex formation, and catalytic properties. Frequently tested in JEE and NEET.