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Fe Iron
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

26
Fe
Iron
Element 26 of Periodic table is Iron with atomic number 26, atomic weight 55.845. Iron, symbol Fe, has a Body Centered Cubic structure and Gray color. Iron is a Transition Metal element. It is part of group 8 (iron family). Know everything about Iron Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
26 Fe - Iron | SchoolMyKids

Iron is a chemical element with symbol Fe (from Latin:ferrum) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth's outer and inner core.

It belongs to group 8 of the periodic table having trivial name .

Iron Facts

Read key information and facts about element Iron

NameIron
Atomic Number26
Atomic SymbolFe
Atomic Weight55.845
PhaseSolid
ColorGray
Appearancelustrous metallic with a grayish tinge
ClassificationTransition Metal
Group in Periodic Table8
Group Nameiron family
Period in Periodic Tableperiod 4
Block in Periodic Tabled -block
Electronic Configuration[Ar] 3d6 4s2
Electronic Shell Structure (Electrons per shell)2, 8, 14, 2
Melting Point1811 K
Boiling Point3134 K
CAS NumberCAS7439-89-6
Neighborhood Elements
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Iron on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 26 to find Iron on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Iron on periodic table look for cross section of group 8 and period 4 in the modern periodic table.

Iron History

The element Iron was discovered by Unknown in year Before 5000 BCE . Iron was first isolated by Egypt in 4000 BCE. Iron derived its name from English word (ferrum in Latin).

There is evidence that iron was known from before 5000 BCE. The oldest known iron objects used by humans are some beads of meteoric iron , made in Egypt in about 4000 BCE. The discovery of smelting around 3000 BCE led to the start of the iron age around 1200 BCE and the prominent use of iron for tools and weapons.

Iron Presence: Abundance in Nature and Around Us

The table below shows the abundance of Iron in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe110000020000
Abundance in Sun100000030000
Abundance in Meteorites22000000077000000
Abundance in Earth's Crust6300000023000000
Abundance in Oceans30.33
Abundance in Humans600006700

Crystal Structure of Iron

The solid state structure of Iron is Body Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
286.65 pm286.65 pm286.65 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 π/2

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameIm_ 3m 26 Fe Iron - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number229
Crystal StructureBody Centered Cubic

Iron Atomic and Orbital Properties

Iron atoms have 26 electrons and the electronic shell structure is [2, 8, 14, 2] with Atomic Term Symbol (Quantum Numbers) 5D4.

Atomic Number26
Number of Electrons (with no charge)26
Number of Protons26
Mass Number56
Number of Neutrons30
Shell structure (Electrons per energy level)2, 8, 14, 2
Electron Configuration[Ar] 3d6 4s2
Valence Electrons3d6 4s2
Valence (Valency)3
Main Oxidation States2, 3
Oxidation States-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7
Atomic Term Symbol (Quantum Numbers)5D4

Bohr Atomic Model of Iron - Electrons per energy level

26 Fe Iron - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Iron - neutral Iron atom

Abbreviated electronic configuration of Iron

The ground state abbreviated electronic configuration of Neutral Iron atom is [Ar] 3d6 4s2. The portion of Iron configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 3d6 4s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Iron

Complete ground state electronic configuration for the Iron atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d6 4s2

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Iron
    Atomic Structure of Iron

    Iron atomic radius is 156 pm, while it's covalent radius is 125 pm.

    Atomic Radius Calculated

    156 pm (1.56 Å)

    Atomic Radius Empirical

    140 pm (1.4 Å)

    Atomic Volume7.0923 cm3/mol
    Covalent Radius125 pm (1.25 Å)
    Van der Waals Radius-
    Neutron Cross Section2.56
    Neutron Mass Absorption 0.0015

    Atomic Spectrum of Iron

    Atomic Spectrum of Iron | SchoolMyKids

    Iron Chemical Properties: Iron Ionization Energies and electron affinity

    The electron affinity of Iron is 15.7 kJ/mol.

    Valence3
    Electronegativity1.83
    ElectronAffinity15.7 kJ/mol

    Ionization Energy of Iron

    Refer to table below for Ionization energies of Iron

    Ionization energy numberEnthalpy - kJ/mol
    1st762.5
    2nd1561.9
    3rd2957
    4th5290
    5th7240
    6th9560
    7th12060
    8th14580
    9th22540
    10th25290
    11th28000
    12th31920
    13th34830
    14th37840
    15th44100
    16th47206
    17th122200
    18th131000
    19th140500
    20th152600
    21st163000
    22nd173600
    23rd188100
    24th195200
    25th851800
    26th895161

    Iron Physical Properties

    Refer to below table for Iron Physical Properties

    Density7.874 g/cm3(when liquid at m.p density is $6.98 g/cm3)
    Molar Volume7.0923 cm3/mol

    Elastic Properties

    Young Modulus211
    Shear Modulus82 GPa
    Bulk Modulus 170 GPa
    Poisson Ratio0.29

    Hardness of Iron - Tests to Measure of Hardness of Element

    Mohs Hardness4 MPa
    Vickers Hardness608 MPa
    Brinell Hardness490 MPa

    Iron Electrical Properties

    Iron is Conductor of electricity. Refer to table below for the Electrical properties ofIron

    Electrical Conductivity10000000 S/m
    Resistivity9.7e-8 m Ω
    Superconducting Point-

    Iron Heat and Conduction Properties

    Thermal Conductivity80 W/(m K)
    Thermal Expansion0.0000118 /K

    Iron Magnetic Properties

    Magnetic TypeFerromagnetic
    Curie Point1043 K
    Mass Magnetic Susceptibility-
    Molar Magnetic Susceptibility-
    Volume Magnetic Susceptibility-

    Optical Properties of Iron

    Refractive Index-

    Acoustic Properties of Iron

    Speed of Sound4910 m/s

    Iron Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Iron

    Melting Point1811 K (1537.85°C, 2800.13 °F)
    Boiling Point3134 K (2860.85°C, 5181.53 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Iron

    Heat of Fusion13.8 kJ/mol
    Heat of Vaporization347 kJ/mol
    Heat of Combustion-

    Iron Isotopes - Nuclear Properties of Iron

    Iron has 28 isotopes, with between 45 and 72 nucleons. Iron has 4 stable naturally occuring isotopes.

    Isotopes of Iron - Naturally occurring stable Isotopes: 54Fe, 56Fe, 57Fe, 58Fe.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    45Fe261945Synthetic
    46Fe262046Synthetic
    47Fe262147Synthetic
    48Fe262248Synthetic
    49Fe262349Synthetic
    50Fe262450Synthetic
    51Fe262551Synthetic
    52Fe262652Synthetic
    53Fe262753Synthetic
    54Fe2628545.845%StableN/A
    55Fe262955Synthetic
    56Fe26305691.754%Stable
    57Fe2631572.119%StableN/A
    58Fe2632580.282%StableN/A
    59Fe263359Synthetic
    60Fe263460Synthetic
    61Fe263561Synthetic
    62Fe263662Synthetic
    63Fe263763Synthetic
    64Fe263864Synthetic
    65Fe263965Synthetic
    66Fe264066Synthetic
    67Fe264167Synthetic
    68Fe264268Synthetic
    69Fe264369Synthetic
    70Fe264470Synthetic
    71Fe264571Synthetic
    72Fe264672Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7439-89-6
    RTECS NumberRTECSNO4565500
    CID Number CID23925
    Gmelin Number-
    NSC Number-