Which of the following features are not shown by quartz glass ?

Options

A. This is a crystalline solid
B. Refractive index is ame in all the directions
C. This has definite heat of fusion
D. This is also called super cooled liquid.

Explanation

To determine which features are not shown by quartz glass, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Nature of Quartz Glass**:
- Quartz glass is an amorphous solid, meaning its particles are not arranged in a regular pattern.

2. **Analyze Each Option**:
- **Option A: "This is a crystalline solid."**
- This statement is incorrect. Quartz glass is not crystalline; it is amorphous. Therefore, this feature is not shown by quartz glass.

- **Option B: "Refractive index is same in all directions."**
- This statement is true. Amorphous solids like quartz glass exhibit isotropic properties, meaning their physical properties, including refractive index, are the same in all directions.

- **Option C: "This has a definite heat of fusion."**
- This statement is false. Amorphous solids do not have a definite heat of fusion because they do not have a fixed melting point. Thus, this feature is also not shown by quartz glass.

- **Option D: "This is also called supercooled liquid."**
- This statement is true. Quartz glass is often referred to as a supercooled liquid because it can flow very slowly over time, similar to a liquid.

3. **Conclusion**:
- The features that are not shown by quartz glass are:
- **Option A: "This is a crystalline solid."**
- **Option C: "This has a definite heat of fusion."**

Thus, the answer is **A and C**.