The mass of a unit cell of CsCl corresponds to the combined masses of :

Options

A. `8Cs^(+) and 1Cl^(-)`
B. `10Cs^(+) and 6Cl^(-)`
C. `1Cs^(+) and 1Cl^(-)`
D. `4Cs^(+) and 4Cl^(-)`

Answer

To determine the mass of a unit cell of cesium chloride (CsCl), we need to analyze the structure of the unit cell and the ions it contains.

### Step-by-Step Solution:

1. **Identify the Structure of CsCl**:
- Cesium chloride crystallizes in a body-centered cubic (BCC) structure. In this structure, cesium ions (Cs⁺) are located at the body center of the cube, while chloride ions (Cl⁻) are located at the corners of the cube.

**Hint**: Remember that in a BCC structure, one type of ion is at the center while the other type occupies the corners.

2. **Count the Number of Ions in the Unit Cell**:
- In a BCC unit cell:
- **Chloride Ions (Cl⁻)**: There are 8 corners in a cube, and each corner ion is shared by 8 unit cells. Therefore, the contribution of Cl⁻ ions from the corners is:
\[ \text{Number of Cl⁻ ions} = 8 \text{ corners} \times \frac{1}{8} = 1 \text{ Cl⁻ ion} \]
- **Cesium Ions (Cs⁺)**: There is 1 Cs⁺ ion located at the body center, which is not shared with any other unit cell. Therefore, the contribution from Cs⁺ is:
\[ \text{Number of Cs⁺ ions} = 1 \text{ Cs⁺ ion} \]

**Hint**: Remember to account for the sharing of ions at the corners when counting the total number of ions in the unit cell.

3. **Combine the Ions**:
- From the above calculations, we find that in one unit cell of CsCl, there is:
- 1 Cl⁻ ion
- 1 Cs⁺ ion
- Therefore, the mass of the unit cell corresponds to the combined mass of these two ions.

**Hint**: The mass of the unit cell is the sum of the masses of the individual ions present in it.

4. **Conclusion**:
- The mass of a unit cell of CsCl corresponds to the combined masses of 1 cesium ion (Cs⁺) and 1 chloride ion (Cl⁻).

**Final Answer**: The mass of a unit cell of CsCl corresponds to the combined masses of 1 Cs⁺ ion and 1 Cl⁻ ion.