Give reasons:
(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.

(i) Mn shows the highest oxidation state of +7 with oxygen because it can form p-pi−d-pi multiple bonds using 2p orbital of oxygen and 3d orbital of Mn. On the other hand, Mn shows the highest oxidation state of +4 with fluorine because it can form a single bond only.
ii) Transition metals show variable oxidation states due to the participation of ns and (n-1)d- electrons in bonding. Lower oxidation state is exhibited when the ns- electrons take part in bonding and higher oxidation states are exhibited when the (n-1) d-electrons take part in bonding.

(iii)Actinoids show irregularities in their electronic configurations because the energy differences between 5f, 6d and 7s subshells are very small. hence, an electron can be occupied in any of the subshells. They have the electronic configuration of 7s² with a variation of occupancy in 5f and 6d orbitals.