$Ag$ crystallises in $fcc$ lattice. What is the total number of tetrahedral voids present in $540 \ g$ of $Ag$ metal (in $N_A$)? $(N_A = \text{Avogadro number}; Ag \text{ atomic weight} = 108 \ g \ mol^{-1})$

In a structure of mixed oxide,oxide ions are in $CCP$. One-fifth of tetrahedral voids are occupied by divalent ion $(A^{2+})$ while half of the octahedral voids are occupied by trivalent ion $(B^{3+})$. The formula of the oxide is:

Find the void volume of a $bcc$ unit cell in $cm^3$ if the volume of the unit cell is $1.5 \times 10^{-22} \ cm^3$.

Which of the following is correct for a two-dimensional closed-packed crystal?

$A$ solid has an $hcp$ lattice. Atoms of $Z$ (anions) form the $hcp$ lattice. Atoms of $X$ (cations) occupy all the octahedral voids in the lattice. Atoms of $Y$ (cations) occupy half of the tetrahedral voids. What is the molecular formula of the solid?

If $z$ represents the number of atoms in a unit cell of a close-packed structure with an $ABCABC$ stacking sequence,then the number of tetrahedral voids in the unit cell is ....