• # question_answer 35) In some of the reactions thallium resembles aluminium, whereas in others it resembles with group $I$ metals. Support this statement by giving some evidences.

(i) Both $Al$and $Tl$form compounds in +3 state i.e., $T{{l}_{2}}{{O}_{3}},A{{l}_{2}}{{O}_{3}},AlC{{l}_{3}},TlC{{l}_{3}}.$ (ii) Both $Al$and $Tl$ form octahedral complexes of the type${{[Al{{F}_{6}}]}^{3-}},{{[Tl{{F}_{6}}]}^{3-}}$. (iii) Like alkali metals, thallium shows (+1) state also; due to inert pair effect, e.g., $T{{l}_{2}}O,N{{a}_{2}}O$ $TlCl,NaCl$