Assertion : Magnetic moment of Dy^{3+} is hig | vedclass

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(A) In lanthanide ions,the $4f$ electrons are well-shielded from the external field by the overlying $5s$ and $5p$ electrons. Thus,the magnetic effect

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If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

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(A) In lanthanide ions,the $4f$ electrons are well-shielded from the external field by the overlying $5s$ and $5p$ electrons. Thus,the magnetic effect of the orbital motion of the electron is not quenched. Consequently,the magnetic moment must be calculated by taking into account both the spin and orbital contributions.The magnetic moment is given by $\mu = g\sqrt{J(J+1)}$,where $g = 1 + \frac{S(S+1) - L(L+1) + J(J+1)}{2J(J+1)}$.For $Dy^{3+}$ $([Xe]4f^9)$,the $4f$ subshell is more than half-filled. In such cases,the spin and orbital angular momenta couple to give a high total angular momentum $J$,resulting in the highest magnetic moment among lanthanoids.Therefore,both the Assertion and Reason are correct,and the Reason is the correct explanation of the Assertion.

Assertion : Magnetic moment of $Dy^{3+}$ is highest among lanthanoids.
Reason : Orbital motion contributes to the magnetic moment.

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Assertion : Magnetic moment of $Dy^{3+}$ is highest among lanthanoids.Reason : Orbital motion contributes to the magnetic moment.