The coordination number of $Ba^{2+}$ ion in Barium fluoride $(BaF_2)$ is $8$. What must be the coordination number of fluoride ion $(F^{-})$?

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.

Total volume of atoms present in a face-centred cubic unit cell of a metal is ($r$ is atomic radius)

In an ionic crystal,ion $A$ is present at the corners of the cubic unit cell,and ion $B$ is present at the centers of the faces. What is the formula of this ionic compound?

In an ${A^{+}}{B^{-}}$ ionic compound, the radii of ${A^{+}}$ and ${B^{-}}$ ions are $180 \ pm$ and $187 \ pm$ respectively. The crystal structure of this compound will be:

Coordination numbers of $Zn^{2+}$ and $S^{2-}$ in the crystal structure of wurtzite are