The radius of a calcium ion is $94 \text{ pm}$ and of the oxide ion is $146 \text{ pm}$. The possible crystal structure of calcium oxide will be

$KBr$ crystallizes in a $fcc$ lattice (similar to $NaCl$). The second nearest neighbor of $K^+$ ion and its number are:

What is the coordination number of the $Ca^{2+}$ ion in the fluorite structure?

In a $ccp$ lattice of $X$ and $Y$,$X$ atoms are present at the corners while $Y$ atoms are at face centers. What would be the formula of the compound if one of the $X$ atoms from a corner is replaced by a $Z$ atom?

What is the coordination number of a cation in an ionic compound if the type of hole occupied by the cation is cubic?

If the distance between $Na^{+}$ and $Cl^{-}$ ions in $NaCl$ crystal is $a \, pm$, what is the length of the cell edge?