What is the coordination number of any particle in the $fcc$ (face-centered cubic) crystal lattice?

In the fluorite structure,the coordination number of the $Ca^{2+}$ ion is.....

In metallic solids,the number of atoms for the face-centered and the body-centered cubic unit cells are,respectively:

In a face-centered cubic lattice of $X$ and $Y$ atoms,$X$ atoms are present at the corners while $Y$ atoms are at the face centers. If two atoms of $X$ are missing from the corners,what is the formula of the compound?

$Pt$ has an $FCC$ structure with an edge length of unit cell $392 \text{ pm}$. What is the radius of $Pt$ (in $\text{ pm}$)?

What is the coordination number of a cation occupying an octahedral void?