A: An ideal crystal has more entropy than a real crystal.
R: An ideal crystals has more disorder.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1)
B. If both Assertion & Reason are true and the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason is false, then mark (4)

Answer

To solve the question, we need to analyze both the assertion (A) and the reason (R) provided in the statement.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states: "An ideal crystal has more entropy than a real crystal."
- In thermodynamics, entropy is a measure of disorder in a system. An ideal crystal is defined as a perfectly ordered arrangement of particles at absolute zero temperature. Therefore, it has the lowest possible entropy (which is zero at absolute zero).
- A real crystal, on the other hand, contains defects and irregularities in its structure, which contribute to a higher degree of disorder and, consequently, a higher entropy compared to an ideal crystal.

**Conclusion for Assertion**: The assertion is **false** because an ideal crystal has less entropy than a real crystal.

2. **Understanding the Reason (R)**:
- The reason states: "An ideal crystal has more disorder."
- As established earlier, an ideal crystal is characterized by perfect order. It does not have any defects or irregularities, which means it has minimal disorder.
- In contrast, real crystals have various defects and irregularities, leading to increased disorder.

**Conclusion for Reason**: The reason is also **false** because an ideal crystal has less disorder than a real crystal.

3. **Final Evaluation**:
- Since both the assertion and the reason are false, the correct answer to the question is that both the assertion (A) and the reason (R) are false.

### Final Answer:
Both assertion and reason are false.

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