If the distance between the corner and the center of a cube is $x$,then the tetrahedral void will be at a distance of .... from the corner of the cube.

The atomic radius of an $fcc$ unit cell is:

$A$ mineral consists of a cubic close-packed structure formed by $O^{2-}$ ions,where half the octahedral voids are occupied by $Al^{3+}$ and one-eighth of the tetrahedral voids are occupied by $Mn^{2+}$. The chemical formula of the mineral is

The molecular formula of a compound is $AB_2O_4$. Atoms of $O$ form a $ccp$ lattice. Atoms of $A$ (cation) occupy $\frac{1}{8}$ of the tetrahedral voids. Atoms of $B$ (cation) occupy a fraction of the octahedral voids. What is the fraction of vacant octahedral voids?

$A$ solid is made of two elements $X$ and $Y$. Atoms of $X$ are in $FCC$ arrangement and $Y$ atoms occupy all tetrahedral sites. What is the possible formula of the compound?

An octahedral void is surrounded by how many spheres?