Group 13 Elements

To understand the relative stabilities of the +1 and +3 oxidation states for Ga (gallium), In (indium), and Tl (thallium), we need to consider the inert pair effect and general periodic trends.

Explanation:

The oxidation states being analyzed are +1 and +3. For elements like Ga, In, and Tl, which belong to the same group, the stability of these oxidation states is influenced by the so-called inert pair effect, which is more pronounced in heavier elements.

Relative Stability of +1 Oxidation State:

• Tl⁺ > In⁺ > Ga⁺: In heavier elements like Tl, the +1 oxidation state is relatively more stable due to the inert pair effect, where the s-electrons are less available for bonding and remain non-bonded. This effect becomes more pronounced as you move down the group from Ga to Tl.

Relative Stability of +3 Oxidation State:

• Ga³⁺ > In³⁺ > Tl³⁺: The +3 oxidation state is most stable at the top of the group (Ga) and decreases in stability as you move down the group to Tl.

Conclusion: This analysis agrees with the given correct answer, emphasizing the stability trends for the +1 and +3 states:

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