Coordination number of $Na^{+}$ ion in rock salt is

In a cubic structure,$W$ atoms are present at the corners of the unit cell,$O$ atoms are at the edge centers,and $Na$ atoms are at the center of the cube. What is the formula of the compound?

What are the number of atoms per unit cell in $BCC$ and $FCC$ respectively?

$Na$ 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 the crystal of $CsCl$,the nearest neighbours of each $Cs^+$ ion are

What are the coordination numbers of $bcc$,$scc$,and $fcc$ respectively?