An element has a $bcc$ structure with $12.08 \times 10^{23}$ unit cells. What is the total number of atoms in these unit cells?

If the coordination number of $Ca^{2+}$ in $CaF_2$ is $8$,then the coordination number of $F^{-}$ ion would be

In a solid $AB$,$A$ atoms are in $ccp$ arrangement and $B$ atoms occupy all the octahedral sites. If two atoms from the opposite faces are removed,then the resultant stoichiometry of the compound is $A_{x} B_{y}$. The value of $x$ is ..... [nearest integer]

The fraction of void space on the body diagonal in an ideal rock salt structure is [Use : $\sqrt{6} = 2.45$]

Select the correct expression for determining the Packing Fraction $(P.F.)$ of an $NaCl$ unit cell (assume ideal),if ions along an edge diagonal are absent.

In a cubic structure of a compound made from $X$ and $Y$,where $X$ atoms are at the corners of the cube and $Y$ atoms are at the face centers of the cube,the molecular formula of the compound is: