In $NaCl$ lattice,the coordination number of $Cl^{-}$ ion is:

Diamond has a three-dimensional structure of $C$ atoms formed by covalent bonds. The structure of diamond has a face-centered cubic $(FCC)$ lattice where $50\,\%$ of the tetrahedral voids are also occupied by carbon atoms. The number of carbon atoms present per unit cell of diamond is $......$

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.

Consider an ionic solid $MX$ with $NaCl$ structure. Create a new unit cell $(Z)$ from the unit cell of $MX$ by following the sequential instructions given below. Ignore charge balance.
$(i)$ Remove all anions $(X)$ except the central one.
$(ii)$ Replace all face-centered cations $(M)$ with anions $(X)$.
$(iii)$ Remove all cations $(M)$ at the corners.
$(iv)$ Replace the central anion $(X)$ with a cation $(M)$.
The value of $\left(\frac{\text{number of anions}}{\text{number of cations}}\right)$ in $Z$ is . . . . .

The number of octahedral sites per sphere in a $fcc$ structure is

The structure of $TlCl$ is similar to $CsCl$. What would be the radius ratio in $TlCl$?