Molten sodium chloride conducts electricity due to the presence of:

Options

A. free electron
B. free ions
C. free molecules
D. atoms of sodium and chlorine

Answer

To solve the question "Molten sodium chloride conducts electricity due to the presence of:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the State of Sodium Chloride**:
- Sodium chloride (NaCl) in its solid state does not conduct electricity because the ions are fixed in place within the crystal lattice and cannot move freely.

2. **Melting of Sodium Chloride**:
- When sodium chloride is heated to its melting point, it becomes molten (liquid). In this state, the rigid structure of the solid breaks down, allowing the ions to move freely.

3. **Presence of Ions in Molten State**:
- In the molten state, sodium chloride dissociates into its constituent ions: sodium ions (Na⁺) and chloride ions (Cl⁻). These ions are now free to move throughout the liquid.

4. **Conduction of Electricity**:
- The conduction of electricity in liquids occurs due to the movement of charged particles. In the case of molten sodium chloride, the free-moving sodium and chloride ions carry electric charge, allowing the substance to conduct electricity.

5. **Conclusion**:
- Therefore, the correct answer to the question is that molten sodium chloride conducts electricity due to the presence of free ions (Na⁺ and Cl⁻).

### Final Answer:
- **Free ions (Na⁺ and Cl⁻)**

---