Consider following statements for $\mathrm{Eu^{3+}}$
\[ \begin{array}{l} \text{(A) The positions of sharp bands in UV-vis spectra of its complexes depend heavily on the ligand environment} \\ \text{(B) Its ground state term symbol is } ^{7}\mathrm{F}_{0} \\ \text{(C) The observed magnetic moment is due to populated higher level} \\ \text{(D) At 2K its magnetic moment approaches to zero} \end{array} \]
The set of correct statements is
(a)A, C and D
(b)B, C and D
(c)A, B and D
(d)A, B and C
Answer
Answer: B ✓ checked by 4AB · confidence high
Explanation
Eu³⁺ (f⁶) has a ⁷F₀ ground state with J = 0, so it is non-magnetic. Its room-temperature moment comes from the thermally populated ⁷F₁ and ⁷F₂ levels, and it approaches zero at 2 K. Its f–f bands barely depend on the ligand. B, C and D (b).