Sodium metal crystallises in body centred cubic lattic with cell edge `4.29 Å` .What is the radius of sodium atom ?

Options

A. `5.72 Å`
B. `0.93 Å`
C. `1.86 Å`
D. `3.22 Å`

Answer

C

Explanation

For bcc lattice,
`r = (sqrt(3)a)/(4) = (1.732 xx 4.29)/(4) = 1.86 Å`.