In the hydrides of VI A group elements the boiling point increases from `H_(2)S` to `H_(2)Po`. It is because of increase in the

Options

A. size of atoms
B. Stability
C. atomic weight of chalcogens
D. Acidic nature

Answer

To solve the question regarding the boiling points of hydrides of VI A group elements (specifically from H₂S to H₂Po), we need to analyze the factors that affect boiling points in this series of compounds.

### Step-by-Step Solution:

1. **Identify the Elements Involved**:
- The hydrides in question are H₂S (Hydrogen sulfide), H₂Se (Hydrogen selenide), H₂Te (Hydrogen telluride), and H₂Po (Hydrogen polonide). These correspond to the elements in Group VI A (or Group 16) of the periodic table.

2. **Understand the Trend**:
- As we move down the group from sulfur (S) to polonium (Po), we observe an increase in the boiling points of these hydrides.

3. **Consider the Factors Affecting Boiling Points**:
- The boiling point of a substance is influenced by intermolecular forces. In the case of these hydrides, the primary forces at play are Van der Waals forces (dispersion forces).

4. **Analyze Atomic Size and Weight**:
- As we move down the group, the atomic size increases due to the addition of electron shells. This increase in size leads to an increase in the atomic weight of the hydrides (H₂S, H₂Se, H₂Te, H₂Po).

5. **Relate Atomic Weight to Intermolecular Forces**:
- Larger atoms have more electrons, which can lead to stronger Van der Waals forces due to increased polarizability. This means that as the atomic weight increases, the strength of the intermolecular forces also increases.

6. **Conclusion**:
- The increase in boiling point from H₂S to H₂Po can be attributed to the increase in atomic weight and size, which enhances the Van der Waals forces between the molecules. Therefore, the correct answer to the question is that the boiling point increases due to the increase in the atomic weight of the hydrides.

### Final Answer:
The boiling point increases from H₂S to H₂Po because of the increase in the atomic weight of the hydrides (Option C).

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