Among the following metals how many metals are extracted by self-reduction method from their respective ores. (Give total number ).Hg , Zn, Cu, Al, Mg , Pb, Fe, Sn

Answer

To determine how many metals among the given list are extracted by the self-reduction method from their respective ores, we need to analyze each metal based on its electropositivity and the typical methods used for their extraction.

### Step-by-Step Solution:

1. **Understanding Self-Reduction Method**:
- Self-reduction is a method where a metal can reduce its own oxide or sulfide to form the metal itself, typically involving less electropositive metals or heavy metals.

2. **List of Metals**:
- The metals provided are: Hg (Mercury), Zn (Zinc), Cu (Copper), Al (Aluminum), Mg (Magnesium), Pb (Lead), Fe (Iron), Sn (Tin).

3. **Analyzing Each Metal**:
- **Hg (Mercury)**:
- Mercury is a heavy metal and is less electropositive. It can be extracted via self-reduction.
- **Zn (Zinc)**:
- Zinc is more electropositive and is typically extracted using carbon reduction, not self-reduction.
- **Cu (Copper)**:
- Copper can undergo self-reduction from its sulfide (Cu₂S) to form metallic copper.
- **Al (Aluminum)**:
- Aluminum is highly electropositive and is extracted via electrolysis, not self-reduction.
- **Mg (Magnesium)**:
- Magnesium is also highly electropositive and is extracted via electrolysis.
- **Pb (Lead)**:
- Lead can undergo self-reduction from its sulfide (PbS) to form metallic lead.
- **Fe (Iron)**:
- Iron is more electropositive and is typically extracted using carbon reduction.
- **Sn (Tin)**:
- Tin is less electropositive but is usually extracted using carbon reduction.

4. **Summary of Findings**:
- Metals that can be extracted by self-reduction:
- Hg (Mercury)
- Cu (Copper)
- Pb (Lead)

5. **Total Count**:
- The total number of metals that can be extracted by the self-reduction method from their respective ores is **3**.

### Final Answer:
**Total number of metals extracted by self-reduction method: 3**

---