Question

An $A{B}_2$ type structure is found in

• A. $NaCl$
• B. $A{l}_2{O}_3$
• C. $Ca{F}_2$
• D. $N_{2}O$

Answer 1

The correct option is C

$Ca{F}_2$

$\Rightarrow A{B}_2$ type structure (fluorite type)
$\Rightarrow Ca{F}_2\Rightarrow C{a}^{2+}$ forms ccp arrangement.
$\Rightarrow$ It covers corners and face centres.
$\Rightarrow F^{-}$ ions are located such that $4C{a}^{2+}$ ions are around it.
It can be said that they occupy tetrahedral sites.