Question

The ' $f$ ' orbitals are half and completely filled, respectively in lanthanide ions
(Given: Atomic no. $Eu, 63; Sm, 62; Tm, 69; Tb, 65; Yb , 70 ; Dy , 66$]

• A. $Eu ^{2+}$ and $Tm ^{2+}$
• B. $Sm ^{2+}$ and $Tm ^{3+}$
• C. $Tb ^{4+}$ and $Yb ^{2+}$
• D. $Dy ^{3+}$ and $Yb ^{3+}$

Answer 1

Answer: (C)

$Tb \rightarrow 4 f ^{9} 6 s ^{2}$
$Tb ^{+4} \rightarrow 4 f ^{7}$
$Yb \rightarrow 4 f ^{14} 6 s ^{2}$
$Yb ^{+2} \rightarrow 4 f ^{14}$