Arrange Ce^{+3}, La^{+3}, Pm^{+3} and Yb^{+3} | vedclass

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

Question

(A) In the lanthanoid series,as the atomic number increases from $La$ $(Z=57)$ to $Lu$ $(Z=71)$,the ionic radii of the $M^{+3}$ ions decrease due to l

Vedclass · Accepted Answer

$Yb^{+3} < Pm^{+3} < Ce^{+3} < La^{+3}$

Vedclass · Answer

(A) In the lanthanoid series,as the atomic number increases from $La$ $(Z=57)$ to $Lu$ $(Z=71)$,the ionic radii of the $M^{+3}$ ions decrease due to lanthanoid contraction. This is because the $4f$ electrons provide poor shielding,causing the effective nuclear charge to increase,which pulls the electrons closer to the nucleus. The order of atomic numbers is $La$ $(57)$ Therefore,the order of ionic radii is $La^{+3} > Ce^{+3} > Pm^{+3} > Yb^{+3}$. In increasing order,this is $Yb^{+3} < Pm^{+3} < Ce^{+3} < La^{+3}$.

Arrange $Ce^{+3}, La^{+3}, Pm^{+3}$ and $Yb^{+3}$ in increasing order of their ionic radii.

Similar Questions

The figure shows three similar lamps $L_1, L_2$,and $L_3$ connected across a power supply. If the lamp $L_3$ fuses,how will the light emitted by $L_1$ and $L_2$ change?

The solution of $\frac{dy}{dx} + 1 = e^{x+y}$ is

In which of the following reactions,the concentration of product is higher than the concentration of reactant at equilibrium? $(K = \text{equilibrium constant})$

$A$ string is vibrating in its fifth overtone between two rigid supports $2.4 ~m$ apart. The distance between successive node and antinode is (in $~m$)

Who discovered the mutagenic effect of $X$-rays?

Vedclass Test Series

Exam Paper Generator

Online Exam Module