Zinc blende on roasting often gives `Zn` metal.

Answer

**Step-by-Step Solution:**

1. **Identify the Ore**: The ore in question is zinc blende, which is chemically represented as ZnS (zinc sulfide).

2. **Understand Roasting**: Roasting is a metallurgical process where a sulfide ore is heated in the presence of excess air. The purpose of roasting is to convert the sulfide ore into its corresponding metal oxide.

3. **Chemical Reaction of Roasting**: When zinc blende (ZnS) is roasted, it reacts with oxygen (O2) from the air. The reaction can be represented as:
\[ 2 \text{ZnS} + 3 \text{O}_2 \rightarrow 2 \text{ZnO} + 2 \text{SO}_2 \]
This equation shows that zinc sulfide reacts with oxygen to produce zinc oxide (ZnO) and sulfur dioxide (SO2).

4. **Stability of Zinc Oxide**: The zinc oxide (ZnO) produced is a stable compound. Unlike some other metal oxides, ZnO does not readily decompose back into zinc metal (Zn) and oxygen (O2) under normal conditions.

5. **Conclusion**: Since roasting of zinc blende results in the formation of stable zinc oxide, it does not yield zinc metal. Therefore, the statement that "zinc blende on roasting often gives Zn metal" is **false**.

**Final Answer**: The statement is false.

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