(i) With reference to structural variability and chemical reactivity, write the differences between lanthanoids and actinoids. (ii) Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state. (iii) Complete the following equation : MnO−4+8H++5e−→ (iv) Out of Mn3+ and Cr3+, which is more paramagnetic and why ? (Atomic nos. : Mn = 25, Cr = 24)

(i) With reference to structural variability and chemical reactivity,

1.	(i) With reference to structural variability and chemical reactivity, write the differences between lanthanoids and actinoids. (ii) Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state. (iii) Complete the following equation : MnO−4+8H++5e−→ (iv) Out of Mn3+ and Cr3+, which is more paramagnetic and why ? (Atomic nos. : Mn = 25, Cr = 24)
Answer» (i) With reference to structural variability and chemical reactivity, write the differences between lanthanoids and actinoids. (ii) Name a member of the lanthanoid series which is well known to exhibit +4 oxidation state. (iii) Complete the following equation : $M n O_{4}^{-} + 8 H^{+} + 5 e^{-} \to$ (iv) Out of $M n^{3 +} a n d C r^{3 +}$ , which is more paramagnetic and why ? (Atomic nos. : Mn = 25, Cr = 24)