Iron
Definition and meaning of Iron in chemistry.
Iron is a chemical element with the symbol Fe and atomic number 26. It is a transition metal and the most common element on Earth by mass, forming much of the planet's outer and inner core.
In more detail
Iron resides in group 8 of the periodic table and is universally recognized for its ferromagnetic properties, which are fundamental to the creation of permanent magnets and electromagnets. It is a highly reactive metal that readily oxidizes in the presence of oxygen and moisture, forming hydrated iron oxides colloquially known as rust. The metal exists in several allotropic forms, such as alpha iron (ferrite) and gamma iron (austenite), which are critical in determining the physical properties of steel alloys. Chemically, iron predominantly forms compounds in the +2 (ferrous) and +3 (ferric) oxidation states, and it actively participates in a wide array of coordination complexes and organometallic compounds. Biologically, iron is an indispensable element for almost all living organisms, primarily serving as the central atom in the heme group of hemoglobin, which facilitates oxygen transport in the blood of vertebrates. It is also an essential component of cytochromes involved in cellular respiration.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Fe |
| Atomic number | 26 |
| Atomic mass | 55.845 u |
| Category | Transition Metal |
| State at room temperature | Solid |
| Melting point | 1538 °C |
| Boiling point | 2862 °C |
| Year discovered | Ancient times |
Iron is the primary constituent of steel, which is universally utilized in the construction of buildings, bridges, and infrastructure due to its unparalleled structural integrity.
Frequently asked questions
Why does iron rust?
Iron rusts because it reacts with oxygen and water in the environment to form hydrated iron(III) oxide, a reddish-brown flaky substance.
How is iron transported in the human body?
Iron is transported in the blood plasma by binding to a glycoprotein called transferrin, which delivers it to cells for the synthesis of hemoglobin and other essential proteins.