In `CaF_(2)` type (fluorite structure) `Ca^(2+)` ions form W structure and `F^(-)` ions are present in all X voids. The coordination number of `Ca^(2=)` is Y and `F^(-)` is Z. W,X,Y and Z respectively are

Options

A. W-ccp, X-octahedral , Y-8,Z-4
B. W-bcc, X-tetrahedral , Y-4,Z-8
C. W-ccp , X-tetrahedral , Y-8,Z-4
D. W-ccp, X-octahedral, Y-4, Z-8

Explanation

To solve the question about the structure of calcium fluoride (CaF₂) and determine the values of W, X, Y, and Z, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of CaF₂**:
- Calcium fluoride crystallizes in a structure known as the fluorite structure. In this structure, the calcium ions (Ca²⁺) occupy the cubic close-packed (CCP) lattice, while the fluoride ions (F⁻) occupy the tetrahedral voids.

**Hint**: Recall that in ionic compounds, cations and anions occupy specific lattice points based on their size and charge.

2. **Identify W (Structure of Ca²⁺)**:
- The calcium ions form a cubic close-packed (CCP) structure. This is also referred to as face-centered cubic (FCC) or cubic close-packed (CCP).

**Hint**: Think about how cations are arranged in a crystal lattice; they often take up the more stable, densely packed arrangements.

3. **Identify X (Structure of F⁻)**:
- The fluoride ions occupy the tetrahedral voids in the CCP structure of calcium. In a CCP structure, there are tetrahedral voids that can be filled by smaller ions.

**Hint**: Consider the arrangement of ions and how smaller ions fit into the voids created by larger ions.

4. **Determine Y (Coordination Number of Ca²⁺)**:
- The coordination number is defined as the number of nearest neighbor ions surrounding a given ion. In the case of Ca²⁺ in CaF₂, each calcium ion is surrounded by 8 fluoride ions.

**Hint**: Visualize the arrangement of ions around a central ion to count how many ions are in contact with it.

5. **Determine Z (Coordination Number of F⁻)**:
- Each fluoride ion is surrounded by 4 calcium ions. Therefore, the coordination number of fluoride ions in this structure is 4.

**Hint**: Again, visualize the arrangement of ions; how many cations surround each anion?

### Final Values:
- W (Structure of Ca²⁺) = CCP (or FCC)
- X (Structure of F⁻) = Tetrahedral voids
- Y (Coordination number of Ca²⁺) = 8
- Z (Coordination number of F⁻) = 4

Thus, the final answer is:
- W = CCP (or FCC), X = Tetrahedral voids, Y = 8, Z = 4.

### Summary:
- W = CCP (or FCC)
- X = Tetrahedral voids
- Y = 8
- Z = 4