Iron in its pure form is a metal and its symbol is Fe. Iron metal contains 26 electrons in its atom. The electrons per shell in iron metal is 2, 8, 14 and 2. The configuration of iron metal is 3d6 4s2. Iron loses two or three electrons to become a positive ion. When two electrons are lost by iron metal iron (II) ion is formed. The number of protons in iron (II) ion is greater than number of electrons. The electrons per shell in iron ion is 2, 8 and 14. The electronic configuration of iron ion is 3d6.