Refractory metals are used in construction of furnances because

Options

A. They can withstand high temperature
B. They are chemically inert
C. Their melting point is high
D. None of these

Answer

To solve the question regarding why refractory metals are used in the construction of furnaces, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Refractory Metals**:
- Refractory metals are a group of metallic elements that are known for their ability to withstand high temperatures and resist wear and deformation.
- Common examples of refractory metals include tungsten, molybdenum, and tantalum.

2. **Properties of Refractory Metals**:
- These metals have high melting points, typically above 2000°C, which makes them suitable for applications that involve extreme heat.
- They also exhibit excellent strength and durability at high temperatures, which is crucial for the structural integrity of furnaces.

3. **Application in Furnaces**:
- Furnaces operate at very high temperatures, often exceeding the melting points of many materials. Therefore, materials used in their construction must be able to endure such conditions without melting or deforming.
- Refractory metals are ideal for this purpose because they do not easily oxidize or corrode when exposed to high temperatures and reactive environments.

4. **Conclusion**:
- The primary reason refractory metals are used in the construction of furnaces is their ability to withstand high temperatures without losing their structural properties.

5. **Select the Correct Option**:
- Based on the understanding of refractory metals and their properties, we can conclude that the correct answer to the question is that they are used because they can withstand high temperatures.

### Final Answer:
Refractory metals are used in the construction of furnaces because they can withstand high temperatures.

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