Because they have more affinity with oxygen then carbon hence cant be obtained by reduction of their ore...so electrolysis
is done and metals are obtain

Introduction to Metal Extraction
The extraction of metals from their ores varies based on their reactivity. Highly reactive metals, such as sodium and potassium, require specific methods for extraction. The most effective method for obtaining these metals is through electrolysis.
Why Electrolysis?
- Electrolysis is a process that uses electricity to break down compounds into their elements.
- For reactive metals, this method is essential as traditional methods like calcination or reduction may not be sufficient due to the strong bonds in their ores.
Understanding the Process
- The process involves dissolving the metal ore in an electrolytic solution or molten state.
- An electric current is passed through the solution, causing the metal ions to migrate towards the cathode (negative electrode) where they gain electrons and are reduced to their elemental form.
- The anode (positive electrode) can either dissolve or release gases depending on the metal being extracted.
Advantages of Electrolysis
- High purity: Electrolysis provides metals with high purity levels.
- Efficiency: It is effective for metals in the upper reactivity series that cannot be reduced by carbon or other reductants.
Comparison with Other Methods
- Calcination: Involves heating the ore in the absence of air, primarily for metal carbonates, but not effective for highly reactive metals.
- Reduction: Typically uses carbon or other reducing agents, which are ineffective for very reactive metals.
- Thermit process: A reduction method using aluminum powder, but it is limited to certain metals and not suitable for all highly reactive metals.
Conclusion
In summary, electrolysis stands out as the most suitable method for extracting highly reactive metals due to its effectiveness and ability to produce high-purity metals.