Aluminium exist in +3 state where as thallium exist in both +1 and +3 oxidation state. Reason for this is
Answers
There is a tendency for post transition elements for inert pair effect due to which the the outermost s orbital electrons does not participate in the reaction or remains inert.
The d orbital which contain 10 electrons and push the s orbital inward that means towards the nucleus. Hence they are more attracted by nucleus. This is called poor shielding effect of d orbital. Thus 6s2 are close to the nucleus. These electrons are less available for bonding. This is known as inert pair effect.
Thus in case of Tl, +1 oxidation state is more stable than +3 oxidation state while in case of aluminium, +3 oxidation state is more stable than +1.
but still thallium shows +3 oxidation but it is very unstable in nature
Aluminium exists in the +3 state whereas thallium exists in both the +1 and +3 oxidation states.
- Aluminium and Thallium both are group 13 elements.
- Thallium has a larger size than aluminium.
- So, due to the innert pair effect, Ta exists in both +1 and +3 oxidation states whereas Al exists only in the +3 oxidation state.
- On the other hand, we can say that the +1 oxidation state of Ta is more stable than the +3 oxidation state.