An ionic solid `A^(o+)B^(Θ)` crystallizes as an bcc structure. The distance between cation and anion in the lattice is `338 pm`. The edge length of cell is

Explanation

In a body centred cubic unit cell, the distance between the cation and anion `(r_(+)+r_(-))` is related to the edge length (a) by
`r^(+)+r^(-)=sqrt(3)xx(a)/(2)," "thereforea=(2)/(sqrt3)(r^(+)+r^(-))` It is given that `r^(+)+r^(-)=338"pm"`
`thereforea=(2)/(sqrt3)xx338"pm"=(676)/(1.732)=390.3"pm"`