The total number of octahedral void$(s)$ per atom present in a cubic close packed structure is

In a face-centred cubic arrangement of $A$ and $B$ atoms,$A$ atoms are at the corners of the unit cell and $B$ atoms are at the face centres. If three of the $B$ atoms are missing from the face centres in the unit cell,what is the simplest formula of the compound?

Vacant space in body centered cubic $(BCC)$ lattice unit cell is about (in $\%$)

The contribution of a particle at the edge center to a particular unit cell is:

In a closed packed array of $N$ spheres,the number of tetrahedral holes is

In the spinel structure,oxide ions are cubical-closest packed where $1/8$ of tetrahedral voids are occupied by $A^{2+}$ cations and $1/2$ of octahedral voids are occupied by $B^{3+}$ cations. The general formula of the compound having spinel structure is