Liquid sodium is used in nuclear reactor. What is its function?

Explanation

**Step-by-Step Solution:**

1. **Understanding Liquid Sodium's Role**: Liquid sodium is employed in nuclear reactors primarily due to its physical and chemical properties.

2. **High Thermal Conductivity**: One of the main functions of liquid sodium in a nuclear reactor is its high thermal conductivity. This means that liquid sodium can efficiently transfer heat generated from the nuclear fission process to the coolant system or to the steam generators.

3. **Low Neutron Absorption Capacity**: Another significant function of liquid sodium is its low neutron absorption capacity. This property is crucial because it allows the neutrons produced during fission to remain available for further fission reactions. In contrast, materials with high neutron absorption would capture these neutrons, reducing the efficiency of the nuclear reaction.

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