(From the Middle English iren) A white, malleable, ductile, metallic chemical element that can be readily magnetized and rusts rapidly in moist or salty air, forming mainly ferric oxide (Fe2O3) and ferric hydroxide (Fe(OH)3). It is vital to plant and animal life; the average human contains about four grams, much of which circulates as hemoglobin in the blood. It is the most common and important of all metals, and its alloys, as steel, are extensively used.
Symbol: Fe (from the
Latin ferrum)
Atomic number: 26
Atomic weight: 55.847
Density (at
room temperature and
pressure): 7.87
g/
cc
Melting point: 1,538°
C
Boiling point: 2,861°
C
Main
valences: +2, +3
Ground state electron configuration: [
Ar]3d
64s
2