The possible oxidation stata Tl are:

Options

A. `+1 and +2`
B. `+2 and +3`
C. `+1 and -1`
D. `+1 and +3`

Answer

To determine the possible oxidation states of thallium (Tl), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Group of Thallium:**
Thallium belongs to Group 13 of the periodic table, which includes elements like boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

**Hint:** Remember that elements in the same group often exhibit similar chemical properties, including oxidation states.

2. **Write the Electronic Configuration:**
The electronic configuration of thallium (Tl) is:
\[ [Xe] \, 4f^{14} \, 5d^{10} \, 6s^2 \, 6p^1 \]
Here, the valence shell is characterized by the outermost electrons, which are in the 6s and 6p orbitals.

**Hint:** The outermost electrons are crucial for determining oxidation states.

3. **Determine the Valence Electrons:**
In the valence shell, thallium has:
- 2 electrons in the 6s subshell
- 1 electron in the 6p subshell

Therefore, the total number of valence electrons is 3 (2 from 6s and 1 from 6p).

**Hint:** Count the electrons in the highest energy level (n=6) to find the valence electrons.

4. **Possible Oxidation States:**
Thallium can lose these valence electrons to form positive oxidation states:
- It can lose the 6p electron to achieve a +1 oxidation state.
- It can lose both the 6s and 6p electrons to achieve a +3 oxidation state.

Thus, the possible oxidation states of thallium are +1 and +3.

**Hint:** Consider how many electrons can be lost from the valence shell to form positive oxidation states.

5. **Consider the Inert Pair Effect:**
The inert pair effect suggests that the 6s electrons are less likely to participate in bonding as we move down the group. This makes the +1 oxidation state more stable compared to the +3 oxidation state.

**Hint:** The inert pair effect is important in heavier p-block elements and affects their oxidation states.

### Conclusion:
The possible oxidation states of thallium (Tl) are +1 and +3.