The number of $Cl^{-}$ ions around one $Na^{+}$ in $NaCl$ crystal lattice is

Copper crystallises in a face-centred cubic lattice with a unit cell length of $361 \text{ pm}$. What is the radius of copper atom in $\text{pm}$?

In a $ccp$ lattice of $X$ and $Y$,$X$ atoms are present at the corners while $Y$ atoms are at face centers. What would be the formula of the compound if one of the $X$ atoms from a corner is replaced by a $Z$ atom?

What is the total number of unit cells shared by each corner particle of a $bcc$ unit cell?

In an ionic compound,the unit cell has $A$ ions at the corners and $B$ ions at the face centers. What is the empirical formula of the compound?

What is the minimum limiting radius ratio for an octahedral arrangement?