In a $bcc$ unit cell,what is the number of atoms per unit cell?

$A$ compound is formed by elements $A$ and $B$. This crystallises in the cubic structure where the $A$ atoms are at the corners of the cube and $B$ atoms are at the body centres. The simplest formula of the compound is

In an ionic crystal,ion $A$ is present at the corners of the cubic unit cell,and ion $B$ is present at the centers of the faces. What is the formula of this ionic compound?

Copper crystallises in a face-centred cubic lattice with a unit cell length of $361 \text{ pm}$. What is the radius of copper atom in $\text{pm}$?

How does the structure of $NaCl$ transform into the $CsCl$ structure?

If the radius ratio is in the range of $0.732 - 1.000$,then the coordination number will be