The number of ores in which Pb is present is Galena, limonite, chalcocite, azurite. ___________

Answer

To determine the number of ores in which lead (Pb) is present among the given options (Galena, Limonite, Chalcocite, Azurite), we will analyze the chemical composition of each ore.

### Step-by-Step Solution:

1. **Identify the Ores and Their Chemical Formulas**:
- **Galena**: The chemical formula is PbS (Lead Sulfide).
- **Limonite**: The chemical formula is often represented as FeO(OH)·nH2O (Iron(III) oxide hydroxide). It does not contain lead.
- **Chalcocite**: The chemical formula is Cu2S (Copper(I) sulfide). It does not contain lead.
- **Azurite**: The chemical formula is 2CuCO3·Cu(OH)2 (Copper(II) carbonate hydroxide). It does not contain lead.

2. **Analyze Each Ore for Lead Content**:
- **Galena**: Contains lead (Pb).
- **Limonite**: Does not contain lead.
- **Chalcocite**: Does not contain lead.
- **Azurite**: Does not contain lead.

3. **Count the Ores Containing Lead**:
- From the analysis, only **Galena** contains lead.

4. **Conclusion**:
- The number of ores in which lead is present is **1** (only Galena).

### Final Answer:
The number of ores in which lead is present is **1**.

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