Give reasons for the following:
(i) Transition elements and their compounds act as catalysts
(ii) `E^(@)` value for `(Mn^(2+) | Mn)` is negative whereas for `(Cu^(2+) | Cu)` is positive.
(iii) Actinoids show irregularities in their electronic configuration.

Assign reasons for the following : (i) Transition metals and many fo their compounds act as good catalyst. (ii) Transition metals generally from coloured compounds.

Give reasons for the following: (i) Transition metals form alloys. (ii) Mn_2O_3 is basic whereas Mn_2O_7 is acidic. (iii) Eu^(2+) is a strong reducing agent.

Give reasons for the following: i. Transition elements act as catalysts ii. It is difficult to obtain oxidation state greater than two for Copper. iii. CrO is basic but Cr_(2)O_(3) is amphoteric.

Give reason for the following : (i) Mn shows the highest oxidation state of +7 with oxygen but with fluorine, it shows the highest oxidation state of +4 (ii) Transition metals show variable oxidation states. (iii) Actinoids show irregularities in their electronic configurations.

Assign reasons for the following : (i) The enthalpies of atomisation of transition elements are high. (ii) The transition metals and many of their compounds act as good catalyst. (iii) From element to element the actinoid contraction is greater than the lanthanoid contraction. (iv) The E^(@) value for the Mn^(3+)//Mn^(2+) couple is much more positive than that for Cr^(3+)//Cr^(2+) . (v) Scandium (Z = 21) does not exhibit variable oxidation states and yet it is regarded as transition element.