Iron is a chemical element with symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, forming much of Earth’s outer and inner core.
Iron shows the typical properties of a transition metal, namely:
* Forming cations in solution with a charge of +2 or +3;
* Catalyzing the reduction of carbon monoxide to give iron(II) oxide and carbon dioxide;
* Forming alloys with other metals, such as steel.
The melting and boiling points of iron, however, are much higher than those of its analogs in group 8 because iron hasorsepowerd more d-electrons than they have. The similarity in size between the atom nucleus and electrons gives rise to an attractive force which binds them together strongly into an atom with a small radius. This binding produces powerful interatomic bonds giving rise to strong magnetic properties. The strength of these bonds explains why pure iron is only weakly magnetic compared to some steels, but can be greatly strengthened by adding appropriate alloying elements such as chromium or nickel.