In a $A_x B_y$ crystal structure,$A^{+y}$ ions occupy all the tetrahedral voids and $B^{-x}$ ions form a $BCC$ unit cell. What is the formula of the compound?

In a $ccp$ structure of $X$ atoms,$Y$ atoms occupy the octahedral voids. If two $X$ atoms at the corners are replaced by $Z$ atoms,the molecular formula of the solid will be:

The fraction of total volume occupied by the atoms present in a simple cubic unit cell is

Atoms of element $B$ form a $ccp$ lattice and atoms of element $A$ occupy $\frac{1}{2}$ of the tetrahedral voids. What is the formula of the compound formed by elements $A$ and $B$?

In a compound made of atoms $A$ and $B$,atoms $A$ form an $fcc$ lattice,while atoms $B$ occupy $25\%$ of the tetrahedral voids and $50\%$ of the octahedral voids. If the crystal is cut such that all face-centered atoms along one axis are removed,the molecular formula of the resulting solid will be ...........

In a closed packed array of $N$ spheres,the number of tetrahedral holes is