The least stable dioxide of group 16 elements is

Options

A. `SO_(2)`
B. `SeO_(2)`
C. `TeO_(2)`
D. `PoO_(2)`

Answer

To determine the least stable dioxide of the group 16 elements, we will analyze the dioxides of the elements in this group: sulfur (SO₂), selenium (SeO₂), tellurium (TeO₂), and polonium (PoO₂).

### Step-by-Step Solution:

1. **Identify the Group 16 Elements and Their Dioxides**:
- The group 16 elements are oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po).
- The dioxides of these elements are:
- SO₂ (sulfur dioxide)
- SeO₂ (selenium dioxide)
- TeO₂ (tellurium dioxide)
- PoO₂ (polonium dioxide)

2. **Understand Stability Factors**:
- The stability of these dioxides can be influenced by two main factors:
- **Dissociation Energy**: This is the energy required to break the bond between the element and oxygen. As we move down the group, the dissociation energy decreases.
- **Size of the Molecule**: As we go down the group, the size of the atoms increases, leading to longer bond lengths. Longer bonds are generally weaker and easier to break.

3. **Analyze the Trend**:
- As we move down the group from sulfur to polonium:
- The dissociation energy decreases.
- The size of the atoms increases, resulting in longer and weaker bonds.
- Therefore, the dioxides become less stable as we move from SO₂ to PoO₂.

4. **Conclusion**:
- Based on the above analysis, we can conclude that the least stable dioxide among the group 16 elements is **PoO₂ (polonium dioxide)**.

### Final Answer:
The least stable dioxide of group 16 elements is **PoO₂ (polonium dioxide)**.

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