Hydrogen occupies the following holes, C and N occupy the following holes

Options

A. Tetrahedral and octahedral
B. Octahedral and tetrahedral
C. Octahedral and octahedral
D. Tetrahedral and tetrahedral

Answer

To solve the problem of which holes are occupied by hydrogen, carbon, and nitrogen, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Sizes of Atoms**:
- Hydrogen (H) has a smaller atomic radius compared to carbon (C) and nitrogen (N). This is a crucial point because the size of the atoms will determine which type of void they can occupy.

2. **Identify Types of Voids**:
- There are two types of voids in a crystal lattice: tetrahedral voids and octahedral voids.
- Tetrahedral voids are smaller than octahedral voids. The ratio of the radius of an atom to the radius of a tetrahedral void is approximately 0.225, while for an octahedral void, it is about 0.414.

3. **Compare the Ratios**:
- Since the radius of hydrogen is smaller, it can fit into the smaller tetrahedral voids.
- In contrast, carbon and nitrogen, which have larger atomic radii, can occupy the larger octahedral voids.

4. **Assign the Atoms to the Voids**:
- Based on the above analysis:
- Hydrogen occupies the tetrahedral voids.
- Carbon and nitrogen occupy the octahedral voids.

5. **Conclusion**:
- Therefore, the final answer is that hydrogen occupies tetrahedral holes, while carbon and nitrogen occupy octahedral holes.

### Final Answer:
- Hydrogen occupies tetrahedral holes, and carbon and nitrogen occupy octahedral holes.