Iron is a metallic chemical element, denoted with the symbol Fe (Latin: Ferrum), which has atomic number 26 and atomic mass 56. It is a metal found in the first group of transition metals. It is the most common chemical element on Earth, forming the largest part of the core of this planet and is the fourth element as abundant in earth’s crust. It is produced in large quantities as a result of fusion in stars with large table, where the production of nickel-56 (which decays into iron) is the latest nuclear fusion reaction is exothermic, becoming the last element that occurs before extinction a supernova resulting reactions that spread radionuclides iron precursors in space.
Like other elements of Group 8 (cadmium, osmium, etc..) Iron has many oxidation states, from -2 to +6, although the most common are 2 and 3. Elemental iron is found in meteorites and some low-oxygen environments, but is reactive with oxygen and water. Freshly cut surfaces of iron have a silver-gray color, are shiny, but it oxidizes in air, reaction products are oxides of iron, also known as rust. Unlike other metal oxide layers, iron oxides occupy a volume greater than the amount of iron, iron oxides and thus can be removed and exposing fresh surfaces for corrosion.