The crystal structure of $AB$ is of $NaCl$ type. If the radius of the $A^+$ ion is $x \ pm$ and the radius of the $B^-$ ion is $y \ pm$, then the edge length of the unit cell will be ..........

The arrangement of $X^{-}$ ions around $A^{+}$ ion in solid $AX$ is given in the figure. If the radius of $X^{-}$ is $250 \ pm$, the radius of $A^{+}$ is: (in $pm$)

In $NaCl$ lattice,the coordination number of $Cl^{-}$ ion is:

In a face-centered cubic $(FCC)$ arrangement,atoms $A$ are present at the corners and atoms $B$ are present at the face centers. If $4$ atoms of $A$ are removed from the corners,what is the empirical formula of the compound?

In a body-centered cubic $(BCC)$ unit cell,the atom at the body center is shared by how many unit cells?

If all ions touching an axis passing through two opposite face-centres of unit cell are removed in $NaCl$ (rock salt) structure in which $Cl^{-}$ ions form $CCP$ and $Na^{+}$ ions occupy all octahedral voids,then the effective number of $Cl^{-}$ ions per unit cell is: