In a cubic close packed structure,the fractional contributions of an atom at the corner and at the face in the unit cell are,respectively:

In a compound $XY$,the atoms of element $Y$ form an $fcc$ structure,while the atoms of element $X$ occupy $25\%$ of the tetrahedral voids. The molecular formula of the compound will be .......

In a compound formed by atoms $A$ and $B$, atoms $A$ form a cubic close-packed $(CCP)$ structure, while atoms $B$ are located at the center of each edge. If the edge length of the cubic unit cell is $115 \ pm$, the distance of atom $A$ from the center of the cube is .......... $pm$.

In a close-packed lattice,how does the size of an octahedral void compare to that of a tetrahedral void?

Calculate the volume occupied by all atoms in a $bcc$ unit cell if the volume of the unit cell is $1.5 \times 10^{-22} \ cm^3$.

The packing efficiency in a body centered cubic $(bcc)$ structure is closest to $.... \, \%$