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?

The unit cell of a binary compound of $A$ and $B$ metals has a $ccp$ structure with $A$ atoms occupying the corners and $B$ atoms occupying the centres of each face of the cubic unit cell. If during the crystallisation of this alloy,two $A$ atoms are missing from the unit cell,the overall composition per unit cell is:

What is the coordination number of a cation present in a tetrahedral void?

In a face-centered cubic $(FCC)$ unit cell,how many unit cells share an atom located at the face center?

If an atom is present in the centre of the cube,the participation of that atom per unit cell is

$A$ compound $M_pX_q$ has a cubic close packing $(ccp)$ arrangement of $X$. Its unit cell structure is shown below. The empirical formula of the compound is:
$M = \square$
$X = \bigcirc$