Iron

  • iron, 26fe
    pure iron chips with a high purity iron cube
    iron
    appearancelustrous metallic with a grayish tinge
    standard atomic weight ar, std(fe)55.845(2)[1]
    iron in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson


    fe

    ru
    manganeseironcobalt
    atomic number (z)26
    groupgroup 8
    periodperiod 4
    blockd-block
    element category  transition metal
    electron configuration[ar] 3d6 4s2
    electrons per shell2, 8, 14, 2
    physical properties
    phase at stpsolid
    melting point1811 k ​(1538 °c, ​2800 °f)
    boiling point3134 k ​(2862 °c, ​5182 °f)
    density (near r.t.)7.874 g/cm3
    when liquid (at m.p.)6.98 g/cm3
    heat of fusion13.81 kj/mol
    heat of vaporization340 kj/mol
    molar heat capacity25.10 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 1728 1890 2091 2346 2679 3132
    atomic properties
    oxidation states−4, −2, −1, 0, +1,[2] +2, +3, +4, +5,[3] +6, +7[4] (an amphoteric oxide)
    electronegativitypauling scale: 1.83
    ionization energies
    • 1st: 762.5 kj/mol
    • 2nd: 1561.9 kj/mol
    • 3rd: 2957 kj/mol
    • (more)
    atomic radiusempirical: 126 pm
    covalent radiuslow spin: 132±3 pm
    high spin: 152±6 pm
    color lines in a spectral range
    spectral lines of iron
    other properties
    natural occurrenceprimordial
    crystal structurebody-centered cubic (bcc)
    body-centered cubic crystal structure for iron

    a=286.65 pm
    crystal structureface-centered cubic (fcc)
    face-centered cubic crystal structure for iron

    between 1185–1667 k
    speed of sound thin rod5120 m/s (at r.t.) (electrolytic)
    thermal expansion11.8 µm/(m·k) (at 25 °c)
    thermal conductivity80.4 w/(m·k)
    electrical resistivity96.1 nΩ·m (at 20 °c)
    curie point1043 k
    magnetic orderingferromagnetic
    young's modulus211 gpa
    shear modulus82 gpa
    bulk modulus170 gpa
    poisson ratio0.29
    mohs hardness4
    vickers hardness608 mpa
    brinell hardness200–1180 mpa
    cas number7439-89-6
    history
    discoverybefore 5000 bc
    main isotopes of iron
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    54fe 5.85% stable
    55fe syn 2.73 y ε 55mn
    56fe 91.75% stable
    57fe 2.12% stable
    58fe 0.28% stable
    59fe syn 44.6 d β 59co
    60fe trace 2.6×106 y β 60co
    category category: iron
    | references

    iron (n/) 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. it is the fourth most common element in the earth's crust.

    in its metallic state, iron is rare in the earth's crust, limited to deposition by meteorites. iron ores, by contrast, are among the most abundant in the earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching 1,500 °c (2,730 °f) or higher, about 500 °c (900 °f) higher than what is enough to smelt copper. humans started to master that process in eurasia only about 2000 bce[not verified in body], and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 bce. that event is considered the transition from the bronze age to the iron age. in the modern world, iron alloys, such as steel, inox, cast iron and special steels are by far the most common industrial metals, because of their high mechanical properties and low cost.

    pristine and smooth pure iron surfaces are mirror-like silvery-gray. however, iron reacts readily with oxygen and water to give brown to black hydrated iron oxides, commonly known as rust. unlike the oxides of some other metals, that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing fresh surfaces for corrosion.

    the body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin. these two proteins play essential roles in vertebrate metabolism, respectively oxygen transport by blood and oxygen storage in muscles. to maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet. iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals.[5]

    chemically, the most common oxidation states of iron are iron(ii) and iron(iii). iron shares many properties of other transition metals, including the other group 8 elements, ruthenium and osmium. iron forms compounds in a wide range of oxidation states, −2 to +7. iron also forms many coordination compounds; some of them, such as ferrocene, ferrioxalate, and prussian blue, have substantial industrial, medical, or research applications.

  • characteristics
  • origin and occurrence in nature
  • chemistry and compounds
  • etymology
  • history
  • symbolic role
  • production of metallic iron
  • applications
  • biological and pathological role
  • see also
  • references
  • bibliography
  • further reading
  • external links

Iron, 26Fe
Pure iron chips with a high purity iron cube
Iron
Appearancelustrous metallic with a grayish tinge
Standard atomic weight Ar, std(Fe)55.845(2)[1]
Iron in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


Fe

Ru
manganeseironcobalt
Atomic number (Z)26
Groupgroup 8
Periodperiod 4
Blockd-block
Element category  Transition metal
Electron configuration[Ar] 3d6 4s2
Electrons per shell2, 8, 14, 2
Physical properties
Phase at STPsolid
Melting point1811 K ​(1538 °C, ​2800 °F)
Boiling point3134 K ​(2862 °C, ​5182 °F)
Density (near r.t.)7.874 g/cm3
when liquid (at m.p.)6.98 g/cm3
Heat of fusion13.81 kJ/mol
Heat of vaporization340 kJ/mol
Molar heat capacity25.10 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1728 1890 2091 2346 2679 3132
Atomic properties
Oxidation states−4, −2, −1, 0, +1,[2] +2, +3, +4, +5,[3] +6, +7[4] (an amphoteric oxide)
ElectronegativityPauling scale: 1.83
Ionization energies
  • 1st: 762.5 kJ/mol
  • 2nd: 1561.9 kJ/mol
  • 3rd: 2957 kJ/mol
  • (more)
Atomic radiusempirical: 126 pm
Covalent radiusLow spin: 132±3 pm
High spin: 152±6 pm
Color lines in a spectral range
Spectral lines of iron
Other properties
Natural occurrenceprimordial
Crystal structurebody-centered cubic (bcc)
Body-centered cubic crystal structure for iron

a=286.65 pm
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for iron

between 1185–1667 K
Speed of sound thin rod5120 m/s (at r.t.) (electrolytic)
Thermal expansion11.8 µm/(m·K) (at 25 °C)
Thermal conductivity80.4 W/(m·K)
Electrical resistivity96.1 nΩ·m (at 20 °C)
Curie point1043 K
Magnetic orderingferromagnetic
Young's modulus211 GPa
Shear modulus82 GPa
Bulk modulus170 GPa
Poisson ratio0.29
Mohs hardness4
Vickers hardness608 MPa
Brinell hardness200–1180 MPa
CAS Number7439-89-6
History
Discoverybefore 5000 BC
Main isotopes of iron
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
54Fe 5.85% stable
55Fe syn 2.73 y ε 55Mn
56Fe 91.75% stable
57Fe 2.12% stable
58Fe 0.28% stable
59Fe syn 44.6 d β 59Co
60Fe trace 2.6×106 y β 60Co
Category Category: Iron
| references

Iron (n/) 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. It is the fourth most common element in the Earth's crust.

In its metallic state, iron is rare in the Earth's crust, limited to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching 1,500 °C (2,730 °F) or higher, about 500 °C (900 °F) higher than what is enough to smelt copper. Humans started to master that process in Eurasia only about 2000 BCE[not verified in body], and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, inox, cast iron and special steels are by far the most common industrial metals, because of their high mechanical properties and low cost.

Pristine and smooth pure iron surfaces are mirror-like silvery-gray. However, iron reacts readily with oxygen and water to give brown to black hydrated iron oxides, commonly known as rust. Unlike the oxides of some other metals, that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing fresh surfaces for corrosion.

The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin. These two proteins play essential roles in vertebrate metabolism, respectively oxygen transport by blood and oxygen storage in muscles. To maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet. Iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals.[5]

Chemically, the most common oxidation states of iron are iron(II) and iron(III). Iron shares many properties of other transition metals, including the other group 8 elements, ruthenium and osmium. Iron forms compounds in a wide range of oxidation states, −2 to +7. Iron also forms many coordination compounds; some of them, such as ferrocene, ferrioxalate, and Prussian blue, have substantial industrial, medical, or research applications.