How will you account for the following:
Zr and Hf sizes are almost same.

How will you account for the following? (i) Actionoids exhibit more number of oxidation states than lanthanoides. ii) Atomic fadii of second and third transition series elements are almost identical.

How will you accout for the following ? (i) Actinoids exhibit more number of oxidation states than lanthanoids. (ii) Atomic radii of second and third transition series elements are almost identical.

How would you account for the following: (i) Cr^(2+) is reducing in nature while with the same d-orbital configuration (d^4) Mn^(3+) is an oxidising agent. (ii) In a transition series of metals, the metal which exhibits the greatest number of oxidation state occurs in the middle of the series.

How would you Account for the following: (i) Of the d^4 species, Cr^(2+) is strongly reducing while manganese (III) is strongly oxidising, (ii) Cobalt (II) is stable in aqueous solution but in the presence of complexing reagents, it is easily oxidised. (iii) The d^1 configuration is very unstable in ions.

How would you account for the following : (i) The electron gain enthalpy with negative sign is less for oxygen than that for sulphur. (ii) Phosphorus shows greater tendency for catenation than nitrogen. (iii) Fluorine never acts as the central atom in polyatomic interhalogen compounds.

Account for the following: Elements of group 17 are monovalent.

How would you account for the following: Among lanthanoids, Ln (III) compounds are predominant. However occasionally in solutions or in solid compounds, +2 and +4 ions are also obtained.

Which of the following pairs has almost same colours ?

How would you name the following compounds?