The number of close neighbours in a body-centred cubic $(BCC)$ lattice of identical spheres is:

In a face-centered cubic lattice,a unit cell is shared equally by how many unit cells?

If a metal has a $fcc$ crystal structure,the coordination number is $12$ because

In an $fcc$ crystal lattice,atoms $A$ are present at the corners and atoms $B$ are present at the face centers. If one atom $A$ is missing from a corner,what is the molecular formula of the compound?

What is the coordination number in a hexagonal close-packed $(h.c.p.)$ structure?

If three elements $A, B, C$ crystallize in a cubic solid lattice with $B$ atoms at the cubic centers, $C$ atoms at the center of edges, and $A$ atoms at the corners, then the formula of the compound is