A compound is formed by two elements `X` and `Y`. Atoms of the element `Y` (as anion) make ccp and those of element `X` (as cation) occupy all the octahedral voids. What is the formula of the compound?

Explanation

To find the formula of the compound formed by elements X and Y, we can follow these steps:

### Step 1: Understand the arrangement of Y
The problem states that atoms of element Y (as anions) make a cubic close packing (CCP). In a CCP arrangement, the number of Y atoms can be calculated as follows:

- **Corners**: There are 8 corners in a cube, and each corner atom contributes \( \frac{1}{8} \) of an atom to the unit cell.
- **Face Centers**: There are 6 face centers in a cube, and each face center atom contributes \( \frac{1}{2} \) of an atom to the unit cell.

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