Group 13 elements show

Options

A. only + 1 oxidation state
B. only +3 oxidation state
C. `+`1 and + 3 oxidation state
D. `+1, + 2` and + 3 oxidation states.

Answer

To answer the question regarding the oxidation states of Group 13 elements, we can break down the explanation step by step:

### Step-by-Step Solution:

1. **Identify Group 13 Elements**:
- Group 13 elements, also known as the boron family, include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

2. **Determine the General Electronic Configuration**:
- The general electronic configuration for Group 13 elements can be represented as \( ns^2 np^1 \) where \( n \) is the principal quantum number. For example, for Aluminum (Al), the configuration is \( [Ne] 3s^2 3p^1 \).

3. **Identify Possible Oxidation States**:
- Group 13 elements can exhibit oxidation states of +1 and +3. The +3 oxidation state arises from the loss of all three valence electrons (2 from \( s \) and 1 from \( p \)), while the +1 oxidation state results from the loss of only the \( p \) electron.

4. **Trend in Oxidation States Down the Group**:
- As we move down the group from boron to thallium, the tendency to exhibit the +1 oxidation state increases. This is due to the inert pair effect, where the \( s \) electrons (the inert pair) do not participate in bonding as effectively.

5. **Inert Pair Effect**:
- The inert pair effect is more pronounced in heavier elements (like thallium) due to poor shielding by the inner \( f \) orbitals (4f). This leads to the \( s \) electrons being less available for bonding, thus favoring the +1 oxidation state.

6. **Conclusion**:
- Therefore, while Group 13 elements can show both +1 and +3 oxidation states, the tendency to show +1 increases and the tendency to show +3 decreases as we move down the group. Thallium (Tl), for instance, predominantly exhibits the +1 oxidation state.

### Final Answer:
The Group 13 elements show +1 and +3 oxidation states, with the +1 state becoming more prevalent as you move down the group due to the inert pair effect.

---