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. Know everything about Iron Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
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.
Read key information and facts about element Iron
Name | Iron |
Atomic Number | 26 |
Atomic Symbol | Fe |
Atomic Weight | 55.845 |
Phase | Solid |
Color | Gray |
Classification | transition metal |
Group in Periodic Table | 8 |
Group Name | iron family |
Period in Periodic Table | 4 |
Block in Periodic Table | d-block |
Electronic Configuration | [Ar] 3d6 4s2 |
Melting Point | 1538 °C |
Boiling Point | 2861 °C |
Electronic Shell Structure | [2, 8, 14, 2] |
CAS Number | CAS7439-89-6 |
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.
The element Iron was discovered by unknown in year 2000 BC in unknown place . Iron derived its name from English word (ferrum in Latin)
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 %) | |
---|---|
Abundance in Universe | 0.0011 |
Abundance in Sun | 0.001 |
Abundance in Meteorites | 0.22 |
Abundance in Earth's Crust | 0.063 |
Abundance in Oceans | 3×10-7% |
Abundance in Humans | 6e-05 |
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.
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)
a | b | c |
---|---|---|
286.65 | 286.65 | 286.65 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
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 Name | Im_ 3m |
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Space Group Number | 229 | |
Crystal Structure | Body Centered Cubic |
Iron atoms have 26 electrons and the electronic shell structure is [2, 8, 14, 2] with Atomic Term Symbol (Quantum Numbers) 5D4.
Atomic Number | 26 |
Number of Electrons (with no charge) | 26 |
Number of Protons | 26 |
Mass Number | 56 |
Number of Neutrons | 30 |
Shell structure (Electrons per energy level) | [2, 8, 14, 2] |
Electron Configuration | [Ar] 3d6 4s2 |
Valence Electrons | 3d6 4s2 |
Oxidation State |
-4;-2;-1
1;2;3;4;5;6;7 |
Atomic Term Symbol (Quantum Numbers) | 5D4 |
Shell Structure of Iron - Electrons per energy level
n | s | p | d | f | |
---|---|---|---|---|---|
1 | K | 2 | |||
2 | L | 2 | 6 | ||
3 | M | 2 | 6 | 6 | |
4 | N | 2 |
The ground state 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.
Complete ground state electronic configuration for the Iron atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d6 4s2
Iron atomic radius is 156 pm, while it's covalent radius is 125 pm.
Atomic Radius |
156 pm (1.56 Å) |
Atomic Volume | 7.09232918466 cm3 |
Covalent Radius | 125 pm (1.25 Å) |
Van der Waals Radius | N/A |
Neutron Cross Section | 2.56 σa/barns |
The electron affinity of Iron is 15.7 kJ/mol
Valence | 3 |
Electronegativity | 1.83 |
ElectronAffinity | 15.7 kJ/mol |
Refer to table below for Ionization energies of Iron
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1 | 762.5 |
2 | 1561.9 |
3 | 2957 |
4 | 5290 |
5 | 7240 |
6 | 9560 |
7 | 12060 |
8 | 14580 |
9 | 22540 |
10 | 25290 |
11 | 2.8×104 |
12 | 31920 |
13 | 34830 |
14 | 37840 |
15 | 4.41×104 |
16 | 47206 |
17 | 1.222×105 |
18 | 1.31×105 |
19 | 1.405×105 |
20 | 1.526×105 |
21 | 1.63×105 |
Refer to below table for Iron Physical Properties
Density | 7.874 g/cm3 |
Molar Volume | 7.09232918466 cm3 |
Young Modulus | 211 GPa |
Shear Modulus | 82 GPa |
Bulk Modulus | 170 GPa |
Poisson Ratio | 0.29 |
Mohs Hardness | 4 MPa |
Vickers Hardness | 608 MPa |
Brinell Hardness | 490 MPa |
Iron is Conductor of electricity. Refer to table below for the Electrical properties of Iron
Electrical Conductivity | 1×107 S/m |
Resistivity | 9.7×10-8 m Ω |
Superconducting Point | N/A |
Thermal Conductivity | 80 W/(m K) |
Thermal Expansion | 0.0000118 K-1 |
Magnetic Type | Ferromagnetic |
Curie Point | 1043 K |
Mass Magnetic Susceptibility | N/A |
Molar Magnetic Susceptibility | N/A |
Volume Magnetic Susceptibility | N/A |
Refractive Index | N/A |
Speed of Sound | 4910 m/s |
Refer to table below for Thermal properties of Iron
Melting Point | 1811 K (1538 °C) |
Boiling Point | 3134 K (2861 °C) |
Critical Temperature | N/A |
Superconducting Point | N/A |
Heat of Fusion | 13.8 kJ/mol |
Heat of Vaporization | 347 kJ/mol |
Heat of Combustion | N/A |
Isotopes of rhodium. Naturally occurring Iron has 4 stable isotope - 54Fe, 56Fe, 57Fe, 58Fe.
Isotope | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|
45Fe | ||||
46Fe | ||||
47Fe | ||||
48Fe | ||||
49Fe | ||||
50Fe | ||||
51Fe | ||||
52Fe | ||||
53Fe | ||||
54Fe | 5.845% | Stable | N/A | |
55Fe | ||||
56Fe | 91.754% | Stable | N/A | |
57Fe | 2.119% | Stable | N/A | |
58Fe | 0.282% | Stable | N/A | |
59Fe | ||||
60Fe | ||||
61Fe | ||||
62Fe | ||||
63Fe | ||||
64Fe | ||||
65Fe | ||||
66Fe | ||||
67Fe | ||||
68Fe | ||||
69Fe | ||||
70Fe | ||||
71Fe | ||||
72Fe |
CAS Number | CAS7439-89-6 |
RTECS Number | RTECSNO4565500 |
DOT Hazard Class | 4.1 |
DOT Numbers | 3089 |
EU Number | N/A |
NFPA Fire Rating | 1 |
NFPA Hazards | N/A |
NFPA Health Rating | 1 |
NFPA Reactivity Rating | 0 |
Autoignition Point | 100 °C |
Flashpoint | N/A |
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7439-89-6 |
CID Number | CID23925 |
Gmelin Number | N/A |
NSC Number | N/A |
RTECS Number | RTECSNO4565500 |
Metalloid |
Nonmetals |
Other Nonmetals | |
Halogens | Noble Gas |
Metals |
|
Alkali Metals | Alkaline Earth Metals |
Transition Metals | Post-Transition Metals |
Lanthanide | Actinide |