Amorphous solids have

Options

A. Orderly arrangement of atoms
B. Repeating unit of unit cell
C. Long range of melting point
D. Anisotropy

Answer

### Step-by-Step Solution:

1. **Understanding Amorphous Solids**:
- Amorphous solids are materials that lack a long-range order in their atomic or molecular arrangement. Unlike crystalline solids, which have a well-defined and repeating structure, amorphous solids have a disordered arrangement.

**Hint**: Recall the difference between crystalline and amorphous solids in terms of atomic arrangement.

2. **Analyzing the Options**:
- **Option 1**: "Orderly arrangement of atoms" - This is incorrect because amorphous solids do not have an orderly arrangement; they are characterized by a lack of long-range order.
- **Option 2**: "Repeating unit of unit cell" - This is also incorrect as amorphous solids do not have a defined unit cell due to their disordered structure.
- **Option 3**: "Long range of melting point" - This statement is correct. Amorphous solids do not have a sharp melting point; instead, they melt over a range of temperatures.
- **Option 4**: "Anisotropy" - This is incorrect because amorphous solids exhibit isotropy, meaning their physical properties are the same in all directions, unlike crystalline solids which are anisotropic.

3. **Conclusion**:
- Based on the analysis of the options, the only correct statement about amorphous solids is that they have a "long range of melting point." Therefore, the correct answer is **Option 3**.

### Final Answer:
**Amorphous solids have a long range of melting point. (Option 3)**

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