Iron Packs in a Body-Centered Cubic Structure $\sqrt{2}(126 \mathrm{pm})=178 \mathrm{pm}$ B) 2(126 Pm)= 252 Pm
C)

Multiple Choice

Iron packs in a body-centered cubic structure.If an iron atom has a radius of 126 pm,what is the distance between lattice points at two opposite corners of the unit cell? (Note: a line drawn between the points would go through the center of the unit cell)

A) $\sqrt{2}(126 \mathrm{pm}) =178 \mathrm{pm}$
B) 2(126 pm) = 252 pm
C) $\frac{\sqrt{3}}{2}(126 \mathrm{pm}) =109 \mathrm{pm}$
D) 4(126 pm) = 504 pm
E) $\sqrt{3}(126 \mathrm{pm}) =218 \mathrm{pm}$