In a sodium chloride crystal, each chloride ion is surrounded by

Options

A. 6 sodium ions
B. 6 chloride ions
C. 8 sodium ions
D. 4 sodium ions.

Explanation

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

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

**Hint:** Remember that in FCC structures, ions are located at specific positions in the unit cell.

### Step 2: Identify the Positions of Cl⁻ Ions
In the FCC structure of NaCl:
- Chloride ions (Cl⁻) are located at:
- 8 corners of the cube (1/8 contribution from each corner)
- 6 face centers (1/2 contribution from each face center)

**Hint:** Count the contributions from each type of position to find the total number of Cl⁻ ions in the unit cell.

### Step 3: Identify the Positions of Na⁺ Ions
In the NaCl structure:
- Sodium ions (Na⁺) occupy the octahedral voids, which are located at:
- The body center of the cube
- The edge centers (12 edges, with 1/4 contribution from each edge)

**Hint:** Visualize the unit cell to see where the Na⁺ ions are located.

### Step 4: Count the Na⁺ Ions Surrounding Each Cl⁻ Ion
Each chloride ion (Cl⁻) is surrounded by sodium ions (Na⁺) in the octahedral voids. In the NaCl structure:
- Each Cl⁻ ion is surrounded by 6 Na⁺ ions.

**Hint:** Use symmetry and the arrangement of ions to determine how many Na⁺ ions are adjacent to each Cl⁻ ion.

### Conclusion
In a sodium chloride crystal, each chloride ion (Cl⁻) is surrounded by **6 sodium ions (Na⁺)**.

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