Most electropositive metal are obtained from their ores by

Options

A. autoreduction
B. smelting with carbon
C. electrolysis of fused salts
D. thermal decomposition

Answer

To solve the question "Most electropositive metals are obtained from their ores by," we will analyze the options provided and determine the correct method.

### Step-by-Step Solution:

1. **Understanding Electropositive Metals**:
- Electropositive metals are those that readily lose electrons to form positive ions. Examples include alkali metals and alkaline earth metals.

2. **Analyzing the Options**:
- **Auto-reduction**: This is a process where a metal oxide is reduced by the metal itself, but it is not commonly used for highly electropositive metals.
- **Smelting**: This process involves heating ores to extract metals, typically used for less reactive metals.
- **Electrolysis**: This method uses electrical energy to drive a non-spontaneous reaction. It is particularly effective for extracting highly reactive and electropositive metals from their ores.
- **Thermal Decomposition**: This involves breaking down compounds by heat, but it is not suitable for extracting highly electropositive metals.

3. **Choosing the Best Method**:
- Among the options, **electrolysis** is the most effective method for obtaining highly electropositive metals. It allows for the extraction of metals in their purest form, as demonstrated in the example of sodium extraction from common salt.

4. **Conclusion**:
- Therefore, the correct answer is that most electropositive metals are obtained from their ores by **electrolysis**.

### Final Answer:
Most electropositive metals are obtained from their ores by **electrolysis**.

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