Which of the following is an amorphous substance ?

Options

A. Fe metal
B. Fused quartz
C. Wurtzite
D. NiAs

Answer

To determine which of the following is an amorphous substance, we first need to understand the definition of an amorphous solid.

### Step-by-Step Solution:

1. **Definition of Amorphous Substance**: An amorphous substance is a non-crystalline solid where the atoms or molecules are not arranged in a definite lattice pattern. This lack of a regular structure gives amorphous solids unique properties compared to crystalline solids.

2. **Examples of Amorphous Substances**: Common examples include glass, plastics, gels, and certain types of quartz. These materials do not have a long-range order in their atomic arrangement.

3. **Analyzing the Options**: We need to look at the options provided in the question to identify which one is an amorphous substance.

4. **Identifying the Correct Option**: Among the options, the second option is mentioned as "fused quartz". Fused quartz is a type of glass made from silicon dioxide that has been melted and cooled rapidly, preventing the formation of a crystalline structure. Therefore, it is classified as an amorphous solid.

5. **Conclusion**: Based on the analysis, the correct answer is the second option, "fused quartz", as it is an amorphous substance.

### Final Answer:
The correct answer is **fused quartz** (option 2).

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