Oxidation State & Inert Pair Effectp-block Group 13 & 14
Why does Aluminium show only the +3 oxidation state and not +1?
Expert Answer
Due to its small size and high ionization energy, the sum of the first three ionization enthalpies is compensated by high hydration or lattice energy. The inert pair effect is not significant enough in Al to stabilize the +1 state (unlike Thallium).