In NaCl crystal each `Cl^-` ion is surrounded by

Options

A. `4Na^+` ions
B. `6Na^+` ions
C. `1Na^+` ions
D. `2Na^+` ions

Explanation

To determine how many Na⁺ ions surround each Cl⁻ ion in a NaCl crystal, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of NaCl**:
- Sodium chloride (NaCl) crystallizes in a face-centered cubic (FCC) lattice structure. In this structure, the chloride ions (Cl⁻) occupy the face centers and corners of the cube.

2. **Identify the Arrangement of Cl⁻ Ions**:
- In the FCC arrangement, each unit cell contains Cl⁻ ions at the corners and the center of each face. There are 8 corners and 6 face centers in a cubic unit cell.

3. **Determine the Position of Na⁺ Ions**:
- The sodium ions (Na⁺) occupy the octahedral voids in the FCC lattice. In a NaCl structure, each Na⁺ ion is located at the center of the cube and at the edge centers.

4. **Count the Surrounding Na⁺ Ions for a Cl⁻ Ion**:
- Each Cl⁻ ion is surrounded by Na⁺ ions located at the octahedral sites. Specifically, for each Cl⁻ ion, there are 6 Na⁺ ions surrounding it. This can be visualized by considering a Cl⁻ ion positioned at a corner of the cube; the nearest Na⁺ ions are located at the center of the cube and at the centers of the edges adjacent to that corner.

5. **Conclusion**:
- Therefore, each Cl⁻ ion in a NaCl crystal is surrounded by **6 Na⁺ ions**.

### Final Answer:
Each Cl⁻ ion in a NaCl crystal is surrounded by **6 Na⁺ ions**.

---