Chemistry - f-block Question with Solution | TestHub

Electronic configuration of the given species are

a. ${Sm}^{2+}\left(\mathrm{Z}=62\right)=\left[\mathrm{Xe}\right]4{\mathrm{f}}^6$ b. ${\mathrm{Eu}}^{2+}\left(\mathrm{Z}=63\right)=\left[\mathrm{Xe}\right]4{\mathrm{f}}^7$

c. ${\mathrm{Yb}}^{2+}\left(\mathrm{Z}=70\right)=\left[\mathrm{Xe}\right]4{\mathrm{f}}^{14}$ d. ${\mathrm{Ce}}^{2+}\left(\mathrm{Z}=58\right)=\left[\mathrm{Xe}\right]4{\mathrm{f}}^{1}5{\mathrm{d}}^1$

On the basis of above electronic configuration, only ${\mathrm{Yb}}^{2+}\left(\mathrm{Z}=70\right)$ has no unpaired electrons i.e. has fully-filled orbitals. Thus, it is diamagnetic in nature.