Assertion : H-bonding occurs in `H_(2)O` due to larger size of O-atom.
Reason : The size of O-atom is larger than H-atom.

Options

A. If assertion is true but the reason is false
B. If assertion is false but reason is true
C. If both assertion and reason are true and the reason is the correct explanation of assertion
D. If both assertion and reason are true and the reason is not the correct explanation of assertion

Answer

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

### Step 1: Analyze the Assertion
The assertion states that hydrogen bonding occurs in water (H₂O) due to the larger size of the oxygen atom.

- **Explanation**: Hydrogen bonding occurs when a hydrogen atom covalently bonded to a highly electronegative atom (like oxygen) interacts with another electronegative atom. The size of the atom is not the primary factor for hydrogen bonding; rather, it is the electronegativity and the ability to form dipole-dipole interactions.

### Step 2: Analyze the Reason
The reason states that the size of the oxygen atom is larger than that of the hydrogen atom.

- **Explanation**: This statement is true. Oxygen is indeed larger than hydrogen in terms of atomic size. However, this fact alone does not explain why hydrogen bonding occurs. The key factor is the electronegativity of oxygen, which is significantly higher than that of hydrogen.

### Step 3: Conclusion
- The assertion is **false** because hydrogen bonding does not occur due to the larger size of the oxygen atom.
- The reason is **true** because the size of the oxygen atom is indeed larger than that of hydrogen.

Thus, the correct answer is that the assertion is false, while the reason is true.

### Final Answer
- Assertion: False
- Reason: True