Which of the following is amorphous in nature?

Options

A. Quartz
B. `CuSO_(4).5H_(2)O`
C. Dry ice
D. fused silica glass

Answer

To determine which of the given options is amorphous in nature, we will analyze each option systematically.

### Step 1: Analyze Quartz (SiO2)
- **Description**: Quartz is a crystalline form of silicon dioxide (SiO2).
- **Nature**: Quartz has a well-defined long-range order in its structure, making it a crystalline solid.
- **Conclusion**: Quartz is **not amorphous**.

### Step 2: Analyze SiO4.5 H2O (Silicate Hydrate)
- **Description**: This compound is a hydrated silicate, which typically has a crystalline structure.
- **Nature**: Hydrated compounds like SiO4.5 H2O are usually crystalline in nature. They can be converted to an amorphous form through processes like rapid cooling, but the compound as stated is crystalline.
- **Conclusion**: SiO4.5 H2O is **not amorphous**.

### Step 3: Analyze Dry Ice (Solid CO2)
- **Description**: Dry ice is the solid form of carbon dioxide (CO2).
- **Nature**: Dry ice is a molecular solid and has a structured arrangement of molecules, which classifies it as crystalline.
- **Conclusion**: Dry ice is **not amorphous**.

### Step 4: Analyze Fused Silica Glass
- **Description**: Fused silica glass is obtained by heating quartz (SiO2) and then rapidly cooling it.
- **Nature**: This process disrupts the long-range order of the crystalline structure, resulting in an amorphous solid.
- **Conclusion**: Fused silica glass is **amorphous**.

### Final Conclusion
Based on the analysis:
- Quartz is crystalline.
- SiO4.5 H2O is crystalline.
- Dry ice is crystalline.
- Fused silica glass is amorphous.

Thus, the correct answer is **fused silica glass**.

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