How many $NaCl$ units are present in one unit cell of $NaCl$?

Which of the following exhibits an $8:8$ coordination type packing?

What is the number of atoms per unit cell in a body-centered cubic $(BCC)$ unit cell?

An element crystallises in a face-centred cubic (fcc) unit cell with cell edge $a$. The distance between the centres of two nearest octahedral voids in the crystal lattice is

If the cation is present in the tetrahedral void,what is the radius ratio ${r_ + }/{r_ - }$?

The radius of $Na^{+}$ is $95 \, pm$ and the radius of $Cl^{-}$ ion is $181 \, pm$. What is the coordination number of $Na^{+}$?