The incorrect stability order of +3 and +1 states of 13th group elements (boron family) is:

Options

A. `Ga^(3+) lt In^(3+) lt Tl^(3+)`
B. `Tl^(+) gt Tl^(3+)`
C. `Ga^(+) ltIn^(+) lt Tl^(+)`
D. `Ga^(3+) gt Ga^(+)`

Answer

To determine the incorrect stability order of +3 and +1 oxidation states of the 13th group elements (boron family), we will analyze the stability of these oxidation states for each element in the group: boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

### Step-by-Step Solution:

1. **Understanding the Oxidation States**:
- The 13th group elements can exhibit +1 and +3 oxidation states.
- The +3 oxidation state is generally more stable for lighter elements like boron and aluminum.
- As we move down the group, the +1 oxidation state becomes more stable due to the inert pair effect.

2. **Inert Pair Effect**:
- The inert pair effect refers to the tendency of the s-electrons (the 'inert pair') to remain non-bonding in heavier p-block elements.
- This effect leads to an increased stability of the +1 oxidation state compared to the +3 state for heavier elements.

3. **Stability Order of Oxidation States**:
- For boron (B) and aluminum (Al), the +3 state is more stable.
- For gallium (Ga), indium (In), and thallium (Tl), the +1 state becomes increasingly stable.
- Therefore, the general trend in stability for the 13th group elements is:
- B: +3 > +1
- Al: +3 > +1
- Ga: +3 > +1
- In: +1 > +3
- Tl: +1 > +3

4. **Evaluating Options**:
- We are given various options to identify the incorrect stability order.
- We need to check each option against the established stability trends.

5. **Identifying the Incorrect Order**:
- If an option states that +3 is more stable than +1 for indium (In) or thallium (Tl), it would be incorrect.
- Conversely, if an option states that +1 is more stable than +3 for boron or aluminum, it would also be incorrect.

6. **Conclusion**:
- Based on the analysis, the incorrect stability order will be the one that contradicts the established trends, particularly for the heavier elements (In and Tl).

### Final Answer:
The incorrect stability order of +3 and +1 states of 13th group elements is the one that suggests +3 is more stable than +1 for indium or thallium.