In the face-centred cubic $(FCC)$ lattice structure of gold, the closest distance between gold atoms is ('a' being the edge length of the cubic unit cell).

What is the number of atoms per unit cell in a face-centered cubic $(FCC)$ crystal lattice?

Predict the close-packed structure of an ionic compound $A^{+} B^{-}$ in which the radius of cation and anion are $148 \ pm$ and $195 \ pm$ respectively.

$A$ crystal is made up of metal ions $M_1$ and $M_2$ and oxide ions. Oxide ions form a $ccp$ lattice structure. The cation $M_1$ occupies $50 \%$ of octahedral voids and the cation $M_2$ occupies $12.5 \%$ of tetrahedral voids of the oxide lattice. The oxidation numbers of $M_1$ and $M_2$ are,respectively:

What is the coordination number of sodium in $Na_2O$?

In a cubic structure,$W$ atoms are present at the corners of the unit cell,$O$ atoms are at the edge centers,and $Na$ atoms are at the center of the cube. What is the formula of the compound?