Sodium crystallizes in a bcc lattice, hence the coordination number of sodium in sodium metal is

Options

A. a. 0
B. b. 4
C. c. 6
D. d. 8

Answer

To determine the coordination number of sodium in a body-centered cubic (BCC) lattice, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the BCC Structure**:
- In a BCC lattice, there is one atom at each corner of the cube and one atom at the center of the cube.
- There are a total of 8 corner atoms and 1 body-centered atom.

2. **Visualize the Arrangement**:
- Draw a cube and place an atom at each of the 8 corners.
- Place one atom in the center of the cube.

3. **Identify the Coordination Number**:
- The coordination number is defined as the number of nearest neighbor atoms that surround a particular atom.
- In the case of the body-centered atom, it will be surrounded by the corner atoms.

4. **Count the Nearest Neighbors**:
- The central atom in the BCC structure touches 8 corner atoms.
- Therefore, the coordination number of the central atom is 8.

5. **Conclusion**:
- Since the coordination number is the same for all atoms in the BCC structure, the coordination number of sodium in sodium metal is 8.

### Final Answer:
The coordination number of sodium in sodium metal is **8**.

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