The substance which does not show sharp melting point is

Options

A. KCl
B. Glass
C. Ice
D. Diamond

Explanation

To determine which substance does not show a sharp melting point, we can analyze the properties of the given options.

### Step-by-Step Solution:

1. **Identify the Types of Solids**:
- Solids can be classified into two main categories: crystalline solids and amorphous solids.
- Crystalline solids have a well-defined structure and exhibit sharp melting points, while amorphous solids do not have a definite structure and thus do not have sharp melting points.

2. **Analyze the Given Options**:
- **KCl (Potassium Chloride)**: This is a crystalline solid. It has a specific arrangement of ions and will melt at a sharp temperature.
- **Ice**: Ice is the solid form of water and is also crystalline. It has a sharp melting point at 0°C under standard conditions.
- **Diamond**: Diamond is a form of carbon and is a crystalline solid. It has a very high and sharp melting point.
- **Glass**: Glass is an amorphous solid. It does not have a sharp melting point; instead, it gradually softens over a range of temperatures.

3. **Conclusion**:
- Among the options provided, glass is the only substance that does not exhibit a sharp melting point. Therefore, the correct answer is **glass**.

### Final Answer:
The substance which does not show a sharp melting point is **glass**.