`AB` crystallizes in a body centred cubic lattice with edge length `a` equal to `387p m` .The distance between two oppositely charged ions in the lattice is :

Options

A. `300p m`
B. `335p m`
C. `250p m`
D. `200p m`

Answer

2

Explanation

For a body centred unit cell, we have
` 4r=sqrt(3)a`
or `r=(sqrt(3))/(4)a`
The distance between two oppositely charged ions in the lattice is
`2r=2((sqrt(3))/(4)a)=sqrt(3)/(2)a`
`= (sqrt(3))/(2)(387 p m)`
`= (1.732)/(2) (387 p m)`
`= 335 p m`