In a cubic close-packed $(ccp)$ structure,if there are $N$ spheres,what is the number of octahedral voids?

In an ionic solid, anions $(B)$ are arranged in an $hcp$ array and cations $(A)$ occupy $1/2$ of the tetrahedral voids. What is the formula of the ionic compound?

In a face-centered cubic $(FCC)$ unit cell (or cubic close packing $(CCP)$ unit cell),the edge length $a$ is equal to:

Find the void volume of $fcc$ unit cell in $cm^3$ if the volume of $fcc$ unit cell is $1.25 \times 10^{-22} \ cm^3$.

What is the number of octahedral voids present in $0.2 \ mol$ of a compound forming $hcp$ structure?

The number of tetrahedral and octahedral voids in a $CCP$ unit cell are respectively: