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]
Solution
Tb $\to$ 4f<sup>9</sup> 6s<sup>2</sup><br/><br/>
Tb<sup>+4</sup> $\to$ 4f<sup>7</sup><br/><br/>
Yb $\to$ 4f<sup>14</sup> 6s<sup>2</sup><br/><br/>
Yb<sup>+2</sup> $\to$ 4f<sup>14</sup><br/><br/>
Hence, the pair Tb<sup>+4</sup> and Yb<sup>+2</sup> have half filled and
completely filled f subshells respectively.
About this question
Subject: Chemistry · Chapter: d and f Block Elements · Topic: Properties of Transition Metals
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