Q

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

11.27  In some of the reactions thallium resembles aluminium, whereas in others it resembles with group I metals. Support this statement by giving some evidences.

Thallium belongs to group 13 of the periodic table. It shows +3 and +1 oxidation state. Due to the inert pair effect, the stability of the +1 oxidation state is more, on moving down the group. We know that aluminium and alkali metals +3 and +1 oxidation states.  Thallium displays both oxidation states. Therefore it resembles both aluminium and alkali metals. Like $Al$, it also forms compounds such as $TlCl_3$ and $Tl_{2}O_3$ also $Tl_{2}O$and $TlCl$