Assertion (A): `H_(2)O` a liquid and `H_(2)S` a gas.
Reason (R): Water molecules are held by H-bonds while in `H_(2)S` molecules no such interactions are present between molecules.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is True.

Explanation

To solve the question, we need to analyze the assertion and reason provided:

**Assertion (A):** `H₂O` is a liquid and `H₂S` is a gas.
**Reason (R):** Water molecules are held by hydrogen bonds while in `H₂S` molecules, no such interactions are present between molecules.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- Water (`H₂O`) is indeed a liquid at room temperature, while hydrogen sulfide (`H₂S`) is a gas. This is a factual statement based on the physical states of these compounds under standard conditions.

2. **Analyzing the Reason:**
- The reason provided states that water molecules are held together by hydrogen bonds. This is true; hydrogen bonding occurs due to the high electronegativity of oxygen compared to hydrogen, leading to strong intermolecular attractions.
- In contrast, `H₂S` does not exhibit hydrogen bonding because sulfur is less electronegative than oxygen. Therefore, the intermolecular forces in `H₂S` are weaker van der Waals forces, which do not provide sufficient attraction to keep the molecules in a liquid state at room temperature.

3. **Conclusion:**
- Both the assertion and the reason are true. However, the reason accurately explains why `H₂O` is a liquid and `H₂S` is a gas. Therefore, the assertion is supported by the reason.

4. **Final Evaluation:**
- Since both the assertion and reason are true, and the reason correctly explains the assertion, we conclude that the correct answer is that both A and R are true, and R is the correct explanation of A.

### Final Answer:
Both Assertion (A) and Reason (R) are true, and R is the correct explanation of A.

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