In zone-refining methode the molten zone

Options

A. consists of impurities only
B. contains more impurity than the original metal
C. contains the purified metals only
D. moves to either side

Answer

### Step-by-Step Solution:

1. **Understanding Zone Refining**: Zone refining is a purification technique used primarily for metals and semiconductors. The process involves melting a small region (or zone) of a solid material and moving this molten zone along the material.

2. **Principle of Zone Refining**: The key principle behind zone refining is that impurities are more soluble in the molten state than in the solid state. This means that when the material is melted, the impurities tend to dissolve in the molten metal.

3. **Behavior of the Molten Zone**: As the molten zone moves along the solid material, the impurities that were initially present in the solid metal will preferentially move into the molten zone. Therefore, the molten zone will contain a higher concentration of impurities compared to the original solid metal.

4. **Analyzing the Options**:
- **Option 1**: Consists of impurities only - This is incorrect because the molten zone will also contain some amount of the pure metal.
- **Option 2**: Contains more impurity than the original metal - This is correct as explained by the principle of zone refining.
- **Option 3**: Contains the purified metal only - This is incorrect because the molten zone will still have impurities.
- **Option 4**: Moves to either side - This is misleading as the molten zone moves in one direction along the solid material.

5. **Conclusion**: Based on the understanding of the zone refining process and the behavior of the molten zone, the correct answer is **Option 2: Contains more impurity than the original metal**.