Give reasons:
i) Generally there is increase in density along 3d series of transition metals. 

Explain the following observations: (i) Generally, there is an increase in density of elements from titanium (Z = 22) to copper (Z = 29) in the first series of transition elements. (ii) Transition elements and their compounds are generally found to be good catalysts in chemical rections.

Give reason: Mn exhibits the higher oxidatoin state of +7 among 3d series transition elements.

Write the general electronic configuration of 3d series of transition elements.

The increasing order of the density of alkali metals

Assign reasons for each of the following: (i) Transition metals generally form coloured compounds. (ii) Manganese exhibits the highest oxidation state of +7 among the 3d-series of transition elements.

Give examples and suggest reasons for the following features of the transition metal chemistry. (i) The lowest oxide of transition metal is basic, the highest is amphoteric / acidic. (ii) A transition metal exhibits highest oxidation state in oxides and fluorides. (iii) The highest oxidation state is exhibited in oxoanions of a metal.

Give reasons: (i) Zirconium (Z = 40) and Hafnium (Z = 72) have almost similar atomic radii. (ii) d-block elements exhibit more oxidation states than f-block elements. (iii) The enthalpies of atomization of the transition metals are high (iv) The variation in oxidation states of transition metals is of different type from that of the non transition metals. (v) Orange solution of potassium dichromate turns yellow on adding sodium hydroxide to it.

How would you account for the following: (i) Among lanthanoids, Ln (III) compounds are predominant. However, occasionally in solutions or in solid compounds, +2 and +4 ions are also obtained. (ii) The E_(M^(2+)//M)^(0) for copper is positive (0.34 V). Copper is the only metal in the first series of transition elements showing this behaviour. (iii) The metallic radii of the third (5d) series of transition metals are nearly the same as those of the corresponding members of the second series.

[A] : During catabolism of food through Krebs cycle, energy is generated by ETS. [R]: Energy is released from electrons, as they pass along a series of reactions