Embibe Experts Solutions for Chapter: d-and f-Block Elements, Exercise 1: Exercise

Actinoid contraction is observed greater from element to element in this series resulting from poor shielding by _____ electrons.

Explain the following: ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ acts as a powerful oxidising agent in acidic medium.

Although $\mathrm{Zr}$belongs to $4\mathrm{d}$ and $\mathrm{Hf}$belongs to$5\mathrm{d}$ transition series but it is quite difficult to separate them. Why?

Which trivalent ion has a maximum size in the Lanthanoid series i.e., Lanthanum ion (${\mathrm{La}}^{+3}$) to Lutetium ion (${\mathrm{Lu}}^{3+}$)? (atomic number of Lanthanum $= 57$ and Lutetium $= 71$)

Write a short note on the reactivity of actinoids.

Explain why: Transition metals and their compounds act as catalyst.

Explain why: ${\mathrm{Zn}}^{2+}$ salts are white whereas ${\mathrm{Cu}}^{2+}$ salts are coloured.

In _____ oxidation state iron catalyses the reaction between iodide and persulphate ions.