Which of the following is an amorphous solid?

Options

A. Diamond
B. Graphite
C. Glass
D. Common salt

Answer

To determine which of the following is an amorphous solid, we first need to understand the definitions and characteristics of amorphous and crystalline solids.

### Step-by-Step Solution:

1. **Define Amorphous Solids**: Amorphous solids are materials that do not have a long-range order or a regular arrangement of particles. Their particles are arranged randomly, which gives them a non-crystalline structure.

2. **Define Crystalline Solids**: Crystalline solids, on the other hand, have a well-defined, orderly arrangement of particles. This regular arrangement leads to distinct geometric shapes and well-defined melting points.

3. **Identify Examples**: Common examples of crystalline solids include:
- Common salt (NaCl)
- Graphite
- Metals like iron, copper, etc.

Examples of amorphous solids include:
- Glass
- Plastics
- Gels

4. **Analyze the Options**: If the options provided include materials like glass, common salt, or graphite, we can classify them based on the definitions above. Glass is known for its irregular particle arrangement, making it an amorphous solid.

5. **Conclusion**: Based on the definitions and examples, the correct answer to the question "Which of the following is an amorphous solid?" is **glass**.

### Final Answer:
Glass is an amorphous solid.