“Fe” is the chemical symbol for iron, an abundant and widely utilized element. This silvery-gray metal is common in daily life, its chemical characteristics providing insight into its widespread applications and natural roles.
The Chemistry of Iron
Iron is identified by the atomic number 26, with an atomic mass of approximately 55.845 atomic mass units. As a transition metal, iron resides in Group 8 of the periodic table.
The electron configuration of a neutral iron atom is [Ar] 3d⁶ 4s². This allows iron to form compounds by losing electrons from its 4s and then 3d orbitals. Iron commonly exhibits two oxidation states: iron(II) (Fe²⁺), or ferrous, and iron(III) (Fe³⁺), or ferric.
Iron is a ferromagnetic material, strongly attracted to magnets and capable of being magnetized due to atomic magnetic moment alignment. It is also malleable (hammered into thin sheets) and ductile (drawn into thin wires). These properties contribute to its versatility.
Iron is reactive, especially with oxygen and moisture, leading to rusting. Rust is primarily hydrated iron(III) oxide, a reddish-brown substance that forms when iron oxidizes. Rusting involves iron combining with oxygen and water, forming compounds like Fe₂O₃·xH₂O. This oxidation can weaken iron structures over time.
Iron’s Role in Nature and Industry
Iron is one of Earth’s most abundant elements, constituting about 5% of its crust and ranking as the fourth most common by mass. It is also the most abundant element by mass in the entire Earth, forming a significant portion of its inner and outer cores. Iron is typically found in minerals such as hematite (Fe₂O₃) and magnetite (Fe₃O₄), serving as primary iron ores.
In biological systems, iron plays a fundamental role. Approximately 70% of the iron in the human body is found in hemoglobin, a protein in red blood cells that transports oxygen from the lungs to tissues. Iron also exists in myoglobin, which stores oxygen in muscle cells. Beyond oxygen transport, iron contributes to metabolic processes like DNA synthesis, electron transport, and immune function.
The industrial applications of iron are extensive, due to its strength, abundance, and ease of extraction. Over 90% of all refined metal today is iron, most used in manufacturing steel. Steel is an alloy of iron with carbon and sometimes other elements, offering enhanced strength and durability.
Steel finds widespread use in construction, forming frameworks for buildings, bridges, and infrastructure. It is also a primary material in manufacturing, including automobiles, machinery, and appliances. Iron’s versatility, stemming from its chemical properties and ability to form alloys like steel, makes it an indispensable material in modern society.