Chemistry - f-block Question with Solution | TestHub

Eu and Lu are the members of lanthanide series (so they show lanthanide contraction) and $\mathrm{La}$ is the representative element of all elements of such series and ${\mathrm{Y}}^{3+}$ ion has lower radii as comparison to ${\mathrm{La}}^{3+}$ because it lies immediately above it in the periodic table. $${\mathrm{Y}}^{3+}<{\mathrm{Lu}}^{3+}<{\mathrm{Eu}}^{3+}<{\mathrm{La}}^{3+}$$