Highly pure metal can be obtained by zone refining

Answer

**Step-by-Step Solution:**

1. **Understanding Zone Refining:**
- Zone refining is a technique used to purify metals and is also known as fractional crystallization. It is particularly effective for obtaining ultra-pure samples of metals.

2. **Principle of Zone Refining:**
- The underlying principle of zone refining is that impurities are generally more soluble in the molten state of the metal than in its solid state. This means that when the metal is melted, impurities will dissolve more readily.

3. **Process of Zone Refining:**
- In the zone refining process, a circular heater is used to create a molten zone in a solid metal bar. The heater is moved in a straight line along the length of the metal bar.
- As the heater moves, the metal melts in the heated zone, and the impurities dissolve in this molten part.

4. **Separation of Impurities:**
- As the molten zone moves along the metal bar, the impurities are carried along with the melt. When the molten zone solidifies, the impurities are left behind in the melted section.
- Eventually, the impurities accumulate at one end of the metal bar, while the rest of the metal remains relatively pure.

5. **Final Steps:**
- The section of the metal bar containing the impurities can be removed, leaving behind a highly pure metal at the other end.

6. **Conclusion:**
- Therefore, the statement that "highly pure metal can be obtained by zone refining" is true.

---