The packing efficiency of simple cubic $(sc)$, body-centred cubic $(bcc)$ and cubic close packing $(ccp)$ lattices follow the order:

The void space in an $fcc$ structure is ..........

The packing efficiency of the face-centered cubic $(fcc)$,body-centered cubic $(bcc)$,and simple/primitive cubic $(pc)$ lattices follows the order:

Calculate the packing efficiency in a metal crystal for a face-centred cubic $(FCC)$ unit cell (assuming that atoms are touching each other).

$A$ compound is formed by elements $A$ and $B$ which crystallizes in a $CCP$ structure. Atoms of $A$ are at the corners and atoms of $B$ are at the face centers. If two atoms of $A$ are missing from the unit cell,what is the molecular formula of the compound?

Atom $(A)$ is present in $ccp$ form,atom $(B)$ is present in all the octahedral voids,and atom $(C)$ is present in all the tetrahedral voids. If all particles touching one of the body diagonal axes are removed,find the empirical formula of the solid.