What is the coordination number of $Cu$ in a face-centered cubic $(fcc)$ lattice?

Identify the type of unit cell that has particles at the centre of each face in addition to the particles at eight corners of a cube?

Consider an ionic solid $MX$ with $NaCl$ structure. Create a new unit cell $(Z)$ from the unit cell of $MX$ by following the sequential instructions given below. Ignore charge balance.
$(i)$ Remove all anions $(X)$ except the central one.
$(ii)$ Replace all face-centered cations $(M)$ with anions $(X)$.
$(iii)$ Remove all cations $(M)$ at the corners.
$(iv)$ Replace the central anion $(X)$ with a cation $(M)$.
The value of $\left(\frac{\text{number of anions}}{\text{number of cations}}\right)$ in $Z$ is . . . . .

$Na$ and $Mg$ crystallize in $BCC$ and $FCC$ type crystals respectively,then the number of atoms of $Na$ and $Mg$ present in the unit cell of their respective crystal is

$A$ solid $AB$ has a $NaCl$ structure. $B$ atoms are at the corners and all face-centered positions of the unit cell,while $A$ atoms occupy all the $O.H.V.$ (Octahedral Voids). If all the atoms from the face-centered positions along one axis are removed,what will be the resulting stoichiometry of the solid?

$A$ solid compound contains atoms $X, Y,$ and $Z$. In its unit cell,atoms $X$ are at the corners,atoms $Y$ are at the body center,and atoms $Z$ are at the face centers. The formula of the compound is: