Find the number of tetrahedral voids per atom in a crystal lattice.

Which of the following represents the hexagonal close-packed $(HCP)$ arrangement of spheres?

In an $fcc$ arrangement of $A$ and $B$ atoms, $A$ atoms are at the corners of the unit cell and $B$ atoms are at the face centers. If one of the $A$ atoms is missing from one corner, what is the simplest formula of the compound?

Atoms $A$ are arranged in an $FCC$ system,and atoms $B$ occupy all the octahedral voids and half of the tetrahedral voids. The formula of the compound is:

The percentage of vacant space for $bcc$ unit cell is ............. $\%$

In a cubic close packing,the unit cell has...