Iron, 26Fe
Pure iron chips with a high purity iron cube
Iron
Pronunciation/ˈərn/
Allotropessee Allotropes of iron
Appearancelustrous metallic with a grayish tinge
Standard atomic weight Ar°(Fe)
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
Block  d-block
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 ​(2861 °C, ​5182 °F)
Density (at 20° C)7.874 g/cm3[3]
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 statescommon: +2, +3
−4,? −2,[4] −1,[4] 0,? +1,[5] +4,[4] +5,[6] +6,[4] +7[7]
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
Van der Waals radius194 [1] pm
Color lines in a spectral range
Spectral lines of iron
Other properties
Natural occurrenceprimordial
Crystal structureα-Fe: ​body-centered cubic (bcc) (cI2)
Lattice constant
Body-centered cubic crystal structure for α-Fe: iron
a = 286.65 pm (at 20 °C)[3]
Crystal structureγ-Fe (912–1394 °C): ​face-centered cubic (fcc) (cF4)
Lattice constant
Face-centered cubic crystal structure for γ-Fe (912–1394 °C): iron
a = 364.68 pm (at 916 °C)[8]
Thermal expansion12.07×10−6/K (at 20 °C)[3]
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
Speed of sound thin rod5120 m/s (at r.t.) (electrolytic)
Poisson ratio0.29
Mohs hardness4
Vickers hardness608 MPa
Brinell hardness200–1180 MPa
CAS Number7439-89-6
History
Discoverybefore 5000 BC
Symbol"Fe": from Latin ferrum
Isotopes of iron
Main isotopes[9] Decay
abun­dance half-life (t1/2) mode pro­duct
54Fe 5.85% stable
55Fe synth 2.73 y ε 55Mn
56Fe 91.8% stable
57Fe 2.12% stable
58Fe 0.28% stable
59Fe synth 44.6 d β 59Co
60Fe trace 2.6×106 y β 60Co
 Category: Iron
| references
Fe · Iron
Mn ←

ibox Mn

iso
26
Fe  [e]
IB-Fe [e]
IBisos [e]
→ Co

ibox Co

indexes by PT (page)
child table, as reused in {IB-Fe}
Main isotopes of iron
Main isotopes[9] Decay
abun­dance half-life (t1/2) mode pro­duct
54Fe 5.85% stable
55Fe synth 2.73 y ε 55Mn
56Fe 91.8% stable
57Fe 2.12% stable
58Fe 0.28% stable
59Fe synth 44.6 d β 59Co
60Fe trace 2.6×106 y β 60Co
Data sets read by {{Infobox element}}
Name and identifiers
Symbol etymology (11 non-trivial)
Top image (caption, alt)
Pronunciation
Allotropes (overview)
Group (overview)
Period (overview)
Block (overview)
Natural occurrence
Phase at STP
Oxidation states
Spectral lines image
Electron configuration (cmt, ref)
Isotopes
Standard atomic weight
  most stable isotope
Wikidata
Wikidata *
* Not used in {{Infobox element}} (2023-01-01)
See also {{Index of data sets}} · Cat:data sets (46) · (this table: )

References

  1. ^ "Standard Atomic Weights: Iron". CIAAW. 1993.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  4. ^ a b c d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.
  5. ^ Ram, R. S.; Bernath, P. F. (2003). "Fourier transform emission spectroscopy of the g4Δ–a4Δ system of FeCl". Journal of Molecular Spectroscopy. 221 (2): 261. Bibcode:2003JMoSp.221..261R. doi:10.1016/S0022-2852(03)00225-X.
  6. ^ Demazeau, G.; Buffat, B.; Pouchard, M.; Hagenmuller, P. (1982). "Recent developments in the field of high oxidation states of transition elements in oxides stabilization of six-coordinated Iron(V)". Zeitschrift für anorganische und allgemeine Chemie. 491: 60–66. doi:10.1002/zaac.19824910109.
  7. ^ Lu, J.; Jian, J.; Huang, W.; Lin, H.; Li, J; Zhou, M. (2016). "Experimental and theoretical identification of the Fe(VII) oxidation state in FeO4". Physical Chemistry Chemical Physics. 18 (45): 31125–31131. Bibcode:2016PCCP...1831125L. doi:10.1039/C6CP06753K. PMID 27812577.
  8. ^ Cardarelli, François (2008). Materials Handbook: A Concise Desktop Reference. London: Springer. p. 65. ISBN 1-84628-668-9.
  9. ^ a b Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.