Which of the following solid has maximum melting points?

Options

A. `NaCl`
B. Ice
C. Dry ice
D. `SiO_(2)`

Answer

To determine which of the given solids has the maximum melting point, we will analyze the melting points of each solid listed in the options: NaCl, Ice, Dry Ice, and SiO2.

### Step 1: Identify the melting points of each solid.
- **NaCl (Sodium Chloride)**: The melting point of NaCl is approximately **801°C**.
- **Ice (Solid Water)**: The melting point of ice is **0°C**.
- **Dry Ice (Solid Carbon Dioxide)**: The melting point of dry ice is **-78.5°C**.
- **SiO2 (Silicon Dioxide)**: The melting point of SiO2 is approximately **1710°C**.

### Step 2: Compare the melting points.
Now, let's compare the melting points we have identified:
- NaCl: 801°C
- Ice: 0°C
- Dry Ice: -78.5°C
- SiO2: 1710°C

### Step 3: Determine the highest melting point.
From the comparison, we can see that:
- Ice has the lowest melting point at 0°C.
- Dry Ice has a melting point of -78.5°C, which is lower than Ice.
- NaCl has a melting point of 801°C, which is higher than both Ice and Dry Ice.
- SiO2 has the highest melting point at 1710°C.

### Conclusion:
The solid with the maximum melting point among the options provided is **SiO2**.

### Final Answer:
**SiO2 (Silicon Dioxide)** has the maximum melting point.

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