Question

Give reasons :

(i) Transition metals and their compounds show catalytic activities.

(ii) Separation of a mixture of Lanthanoid elements is difficult.

(iii) Zn, Cd and Hg are soft and have low melting point.

Answer 1

(i) The catalytic activity of transition elements and their compounds is ascribed to their ability to adopt multiple oxidation states and to form complexes.

(ii) Separation of a mixture of Lanthanoids is difficult because the change in radii is very small due to which their chemical properties are similar.

(iii) In Zn, Cd and Hg, the electrons in (n – 1)d- subshell are all paired and hence are not involved in interatomic metallic bonding due to which they are soft and have low melting point.