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) given in the statement.

### Step 1: Understand the Assertion (A)
The assertion states that "An ideal crystal has more entropy than a real crystal."

- **Entropy** is a measure of disorder or randomness in a system. In thermodynamics, an ideal crystal is defined as a perfectly ordered structure at absolute zero temperature, where all particles are arranged in a perfectly ordered manner.

### Step 2: Understand the Reason (R)
The reason states that "An ideal crystal has more disorder."

- This statement is contradictory to the definition of an ideal crystal. An ideal crystal is characterized by its perfect order and minimal disorder. In contrast, a real crystal contains defects and irregularities, leading to greater disorder compared to an ideal crystal.

### Step 3: Compare the Two Statements
Now, let's compare the assertion and the reason:

- The assertion (A) claims that an ideal crystal has more entropy than a real crystal, which is incorrect because an ideal crystal has the least entropy (or disorder).
- The reason (R) states that an ideal crystal has more disorder, which is also incorrect since an ideal crystal is perfectly ordered.

### Step 4: Conclusion
Since both the assertion and the reason are incorrect, we can conclude that:

- The correct answer is that both A and R are false.

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