Its atomic radius is 0.235 nm and the (+1) ionic radius is 0.133 nm. In the solid state Potassium has a body-centered cubic crystal structure with a = 0.533 nm and a nearest neighbor distance of 0.277 ...

Pure iron can have two different crystal structures ... C it returns to body-centered cubic. Low carbon steel alloys have a composition close to the Eutectoid composition: Fe - 0.77 wt% C. The ...