Sodium metal crystallises in body centred cubic lattice with the cell edge , 4.29 Å. What is the radius of sodium atom? What is the length of the body diagonal of the unit cell ?

Sodium metal crystallises in body centred cubic lattice with the cell

1.	Sodium metal crystallises in body centred cubic lattice with the cell edge , 4.29 Å. What is the radius of sodium atom? What is the length of the body diagonal of the unit cell ?
Answer» Solution :For BODY centred cubic lattice, the RELATIONSHIP between the cell EDGE (a) and the radius of the atom is `r=sqrt3/4a=1.732/4xx4.29`=1.86 Å Length of the body DIAGONAL =4r =4 x 1.86 Å=7.44 Å