Number of colourless lanthanoid ions among th | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The colour of lanthanoid ions depends on the presence of unpaired $f$-electrons ($f-f$ transitions).Electronic configurations of the given ions ar

Vedclass · Accepted Answer

$2$

Vedclass · Answer

(B) The colour of lanthanoid ions depends on the presence of unpaired $f$-electrons ($f-f$ transitions).Electronic configurations of the given ions are:$La^{3+} = [Xe] 4f^0$ (No unpaired electrons)$Nd^{3+} = [Xe] 4f^3$ ($3$ unpaired electrons)$Sm^{3+} = [Xe] 4f^5$ ($5$ unpaired electrons)$Eu^{3+} = [Xe] 4f^6$ ($6$ unpaired electrons)$Lu^{3+} = [Xe] 4f^{14}$ (No unpaired electrons)Ions with $f^0$ or $f^{14}$ configurations are colourless because they lack unpaired electrons for $f-f$ transitions.Thus,$La^{3+}$ and $Lu^{3+}$ are colourless.The total number of colourless ions is $2$.

Number of colourless lanthanoid ions among the following is . . . . .
$Eu^{3+}, Lu^{3+}, Nd^{3+}, La^{3+}, Sm^{3+}$

Similar Questions

Which of the following is $NOT$ a lanthanoid element?

Assertion : Magnetic moment values of actinides are lesser than the theoretically predicted values.
Reason : Actinide elements are strongly paramagnetic.

The element having electronic configuration $ns^2(n-1)d^{1-10}(n-2)f^{1-14}$ belongs to:

The number of elements from the following that do not belong to lanthanoids is:
$Eu, Cm, Er, Tb, Yb$ and $Lu$

Explain the size of actinoid elements and their ions.

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Number of colourless lanthanoid ions among the following is . . . . .$Eu^{3+}, Lu^{3+}, Nd^{3+}, La^{3+}, Sm^{3+}$