Compare the chemistry of actinoids with that of lanthanoidswith special reference to (i) electronic configuration (ii) oxidation state (iii) atomci andionic sizes (iv) chemical reactivity.

Compare the chemistry of actinoids with that of lanthanoidswith specia

1.	Compare the chemistry of actinoids with that of lanthanoidswith special reference to (i) electronic configuration (ii) oxidation state (iii) atomci andionic sizes (iv) chemical reactivity.
Answer» Solution :(i) Electronic configuration. The general electronicconfiguration of LANGTHANOIDS is `[Xe]^(54) 4f^(1-14) 5d^(0-1) 6s^(2)`WHEREAS that of actinoids is `[Rn]^(86) 5f^(1-14) 6 s^(0-1) 7s^(2)` . Thus, langthanoids belong to 4f- series whereas actinoids belong to 5f - series. (ii) Oxidation staes. Lnathanoids show limited oxidation states`( + 2, +3, +4)` out of which `+3` is most common. This is becasue of LARGE energy gap between 4 fand 5d subshells. On the other hand, actinoids show a large number of oxidation staes becasue of small energy gap between 5f , 6d and 7s subshell. (iii) Atomic and ionic sizes. Both show decrease in size of their atoms or ions in `+3` oxidation state. In langthanoids, the decrease is called langthanoid contraction whereas in actinoids, it is called actinoid contraction . However , the contraction is greater from element to element in actinoids due to poorer shielding by 5f electrons thanthat by 4f electrons in langthanoids. (iv) CHEMICAL REACTIVITY. Refer to page.