Question

Antifluorite structure is derived from fluorite structure by:

• A. Heating fluorite crystal lattice
• B. Subjecting fluorite structure to high pressure
• C. Interchanging the positions of positive and negative ions in the lattice
• D. Introducing the impurities to the lattice

Answer 1

The correct option is C Interchanging the positions of positive and negative ions in the lattice

Antifluorite structure is derived from fluorite structure by inter-changing the positions of positive and negative ions in the lattice.
$Ca{F}_2$​ has fluorite structure. The $C{a}^{2+}$ ions are arranged in ccp arrangement and the $F^{-}$ ions occupy all the tetrahderal holes.
$N{a}_{2}O$ has antifluorite structure. The $O^{2-}$ ions are arranged in ccp arrangement and the $N{a}^{+}$ ions occupy all the tetrahederal holes.