Iron, Fe
Index
Iron is a metal in group VIII of the periodic table with atomic number 26, an atomic weight of 55.85, and a density of 7.86. It has a melting point of 1539 C.

The electronic configuration of the Fe atom is (Ar)(3d)6(4s)2, and it has an atomic radius of 0.126 nm. The radius of Fe2+ is 0.076 nm, and that of Fe3+ is 0.064 nm.

At room temperature, a-Fe has a body-centered -cubic crystal structure with a basis of a single Fe atom.  At 
910 C the material transforms to g-Fe which has the fcc crystal structure. The 1400 C transformation to d-Fe returns the crystal to the bcc crystal structure.

At room temperature, E = 208 GPa, sy = 50 MPa, UTS = 200 MPa, and a fracture strain of 0.3.
From: Callister, "Materials Science and Engineering," Wiley (1997)