In a simple cubic unit cell,how many unit cells share each lattice point located at the corner?

The first three nearest neighbour distances for a body-centered cubic $(BCC)$ lattice are respectively:

The number of spheres contained $(i)$ in one body centred cubic unit cell and $(ii)$ in one face centred cubic unit cell,is

$A$ binary compound $(A^{+} B^{-})$ has a zinc blende structure where $B^{-}$ ions form the lattice and $A^{+}$ ions occupy $25\%$ of the tetrahedral voids. What is the formula of the compound?

$A$ solid $AB$ has a $ZnS$ type structure. If the radius of the $B^-$ ion is $100 \, pm$, what is the minimum radius of the $A^+$ cation in $pm$?

If an atom is present in the centre of the cube,the participation of that atom per unit cell is