$Na$ 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

In a face-centered cubic arrangement of atoms $A$ and $B$,atoms $A$ are at the corners of the unit cell and atoms $B$ are at the face centers. If one atom $A$ is missing from one corner of the unit cell,what is the simplest formula of the compound?

What is the coordination number of a sphere in a simple cubic lattice?

Argon crystallizes in such a way that the positions of the atoms are at $(0, 0, 0)$,$(0, 1/2, 1/2)$,$(1/2, 0, 1/2)$,and $(1/2, 1/2, 0)$. The type of unit cell is:

In a cubic structure of a compound made from $X$ and $Y$,where $X$ atoms are at the corners of the cube and $Y$ atoms are at the face centers of the cube,the molecular formula of the compound is:

If the radius of an anion is double that of a cation,the coordination number of the cation and the type of hole occupied are respectively: