Na and Mg crystallize in bcc and fcc type crystals respectively, then the number of atoms of Na and Mg present in the unit cell of their respective crystal is
4 and 2
9 and 14
14 and 9
2 and 4
BCC -? Points are at corners and one in the centre of the unit cell.
Number of atoms per unit cell
FCC ? - Points are at the corners and also the centre of the six faces of each cell.
Number of atoms per unit cell
Therefore, Option(4) is correct