Sodium metal crystallises in a body centred cubic lattice with unit cell edge length of 4 Å . The radius of sodium atom is _ _ _ × 10 - 1 Å . (Nearest integer)

Step-by-step solution

Edge length of the unit cell ( a )   =   4   x   10 - 8 cm Radius of sodium atom ( r ) = ? Since, sodium crystallises in body centered cubic arrangement. The radius of the atom and the edge length of the cubic unit cell are related as follows, For bcc structure, 4 r = 3 a ⇒ r = 3 4 a r = 1 . 732 × 4 × 10 - 8 4 r = 1 . 732 × 10 - 8   cm r = 17 . 3 Å .