Which of the following is an amorphous solid ?

Options

A. Graphite ©
B. Quartz glass `(SiO_2)`
C. Chrome alum
D. Silicon carbide (SiC)

Explanation

To determine which of the following options is an amorphous solid, we will analyze each option based on the characteristics of amorphous solids.

### Step-by-Step Solution:

1. **Understanding Amorphous Solids**:
- Amorphous solids lack a long-range order in their atomic arrangement. They have a short-range order and do not have a definite geometric shape. They are often soft and can exhibit a tendency to flow over time.

2. **Analyzing the Options**:
- **Option 1: Graphite**
- Graphite is a covalent crystalline solid. It has a layered structure and exhibits long-range order. Therefore, it is not an amorphous solid.

- **Option 2: Quartz Glass (SiO2)**
- Quartz glass is made of silicon dioxide (SiO2) and is known to be an amorphous solid. It does not have a crystalline structure and can flow over time, fitting the definition of an amorphous solid.

- **Option 3: Chromelum**
- Chromelum is a type of alloy and is also a crystalline solid. It has a well-defined structure and is not amorphous.

- **Option 4: Silicon Carbide**
- Silicon carbide is another crystalline solid. It has a regular arrangement of atoms and does not exhibit the characteristics of an amorphous solid.

3. **Conclusion**:
- Among the given options, the only amorphous solid is **Quartz Glass (SiO2)**.

### Final Answer:
The amorphous solid among the options is **Quartz Glass (SiO2)**.

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