Find the radius of an atom in $fcc$ unit cell having edge length $393 \ pm$. (in $pm$)

What is the limiting radius ratio for a tetrahedral shape?

In the fluorite structure,the coordination number of $Ca^{2+}$ ion is

An alloy of gold and copper crystallizes in a cubic lattice in which the gold atoms occupy the lattice points at the corners of a cube and copper atoms occupy the centers of each of the cube faces. Determine the formula of this compound.

$A$ compound of $A$ and $B$ crystallises in a cubic lattice in which $A$ atoms occupy the lattice points at the corners of the cube. The $B$ atoms occupy the centre of each face of the cube. The probable empirical formula of the compound is

Calculate the number of atoms per unit cell in a face-centered cubic $(fcc)$ unit cell.