The number of octahedral voids in a unit cell of a cubical closest packed structure is

If the number of atoms per unit cell in a crystal is $2$,the structure of the crystal is:

$Xe$ crystallizes in an $fcc$ structure. If the edge length of the unit cell of $Xe$ is $620 \, pm$, then the distance between two nearest $Xe$ atoms is .............. $pm$.

Which statement is not correct?

The coordination number in a simple cubic $(scp)$ lattice is .......

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