JEE Main · 2022 · 27 Jun 2022 · Shift 2 · d and f Block Elements

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)

Answer: (C)

Solution

For half-filled f orbitals (

f^{7}

): Tb (65) has configuration

[Xe] 4 f^{9} 6 s^{2}

, so

Tb^{4 +}

has

4 f^{7}

(half-filled). For completely filled f orbitals (

f^{14}

): Yb (70) has configuration

[Xe] 4 f^{14} 6 s^{2}

, so

Yb^{2 +}

has

4 f^{14}

(completely filled). Therefore, the answer is

Tb^{4 +}

and

Yb^{2 +}

JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Single correct option