Chemistry - f-block Question with Solution | TestHub

Eu & Yb show both $+2\&+3$ oxidation state

${\mathrm{r}}_{{\mathrm{Ce}}^{3+}}<{\mathrm{r}}_{{\mathrm{Eu}}^{3+}}$

In general ${\mathrm{Ln}}^{3+}$ ions having " x " electrons & $(14-\mathrm{x})$ electrons in 4f orbital have the same colour.

Lanthanoids are silvery white \& tarnish rapidly in air.