An element has a body centered cubic (bcc)
structure with a cell edge of 288 pm. The atomic
radius is :
(1) ``\frac{\sqrt3}{4} \times 288`` pm
(2) ``\frac{\sqrt2}{4} \times 288`` pm
(3) ``\frac{\sqrt4}{3} \times 288`` pm
(4) ``\frac{4}{\sqrt2}\times 288`` pm