Iron Chemical Properties (25 Facts You Should Know)

Iron is a very important element belonging to the d block of the periodic table. Let us discuss some important facts about Iron in this article.

Iron is seen to possess a Body-centered cubic structure (depending on temperature range between room temperature – 912°C. But the structure changes to Face-centred cubic as the temperature increases above 912°C. Iron has commercial use as well as biological importance.

In appearance, iron is a lustrous and quite hard metal. In the following sections, important properties of iron, like melting and boiling point, electronegativity, magnetic property, and various chemical properties, are discussed in detail.

Iron symbol

The symbol used to denote the element iron in the periodic table is Fe. In Latin, iron is known as Ferrum. Hence the symbol is written as Fe and not the initial words of iron.

Iron symbol

Iron group in periodic table

The chemical element iron belongs to group 8 of the periodic table. Elements in this group are placed on the basis that they have a complete octet and the valence electrons in iron are 8.

Iron period in periodic table

Iron is placed in period 4 of the periodic table along with various other transition elements.

Iron block in periodic table

The block in which the element iron is placed in the periodic table is d block. Fe is found in the d block because its valence electron is seen to enter the subshell d.

Iron atomic number

The Fe element has a atomic number of 26. Hence the number of electrons it will possess is 26.

Iron atomic weight

The atomic weight of iron is observed to be 55.8 g/mol. All the atoms possess a unique atomic weight.

Iron electronegativity according to Pauling

The electronegativity of iron, according to Pauling, is 1.83. So, the term electronegativity refers to how strongly bonding electrons can be pulled towards themselves by atoms.

Iron atomic density

The density of the element iron is 7.87 g/cm3 (at room temperature). The atomic density of any element can be conveniently determined by dividing mass by the quantity volume.

Iron melting point

Iron melts at a temperature of 1538°C. The intermolecular interaction in the iron molecules is quite strong. To overcome this bonding, it requires a high temperature. Hence giving rise to a high melting point.

Iron boiling point

The element iron boils at a temperature of 2862°C. The crystal of this metal is closely packed. So, to overcome the strong electrostatic forces, a higher temperature is required.

Iron Vanderwaals radius

The Van der Waals radius of Iron is 194 pm.

Iron covalent radius

The covalent radius of Iron in the case of high spin is around 152 pm, and in low spin, it is observed to be approximately 132 pm. A covalent radius is the distance between atoms when they form a single covalent bond.

Iron isotopes

The term isotopes is used to describe the atoms which possess same atomic number but there is variation in mass number. Let us see the isotopes of Iron.

The number of isotopes in the element iron is 4 (stable and naturally occurring).

  • 54Fe

The molecular weight of this isotope is around 53.9 g/mol. In appearance, it is a powder grey in color (it is not radioactive). It has many commercial and biological applications.

  • 56Fe

The abundance (natural) of this isotope is about 91%. The number of neutrons is 30, and the protons are 26.

  • 57Fe

The molecular weight of this isotope is 56 g/mol. It is a solid and is quite stable.

  • 58Fe

The abundance of this isotope is 0.28%. It has 26 protons and 32 neutrons. This isotope is stable.

Iron electronic shell

The term electronic shell describes the shells around the nucleus containing a specific number of electrons. Let us discuss for the element iron.

The number of shells in the element iron is 4. The arrangement pattern of electrons in each shell includes 2, 8, 14, and 2 in each of the 4 shells, respectively.

Iron energy of first ionisation

The first ionisation energy for iron is 762.5 kJ/mol. So, this is the energy required to take out the outermost electron in this element.

Iron energy of second ionisation

The second ionisation energy for iron is 1561.9 kJ/mol. So, this energy will be required to remove the loosely bonded electron where the first electron is already removed.

Iron energy of third ionisation

The third ionisation energy for iron is 2957 kJ/mol.

Iron oxidation states

The oxidation states of the element iron include -4, -2, -1, 0, +1, +2, +3, +4, +5, +6, +7.

Iron electron configurations

The iron electron configuration is [Ar] 3d6 4s2. The electron configuration gives us an idea of the exact arrangement of electrons in the orbitals.

Iron CAS number

The CAS number for the element iron is 7439-89-6. It is a unique number consisting of 10 digits which is very helpful for identification purposes.

Iron ChemSpider ID

The ChemSpider ID for Fe is 22368.

Iron allotropic forms

An element can exist in various forms, and this property is termed an allotropic form of it. Let us discuss it for Fe element.

The element iron has 3 allotropic forms, namely alpha, delta, and gamma (depending on the temperature).

  • Alpha iron: The crystal structure of this allotropic form is body-centered cubic. It is ferromagnetic in nature.
  • Delta iron: It is observed to be stable at a temperature of around 1390°C.
  • Gamma iron: The crystal structure of this allotropic form is face-centered cubic. Its stability ranges from a temperature of 910°C – 1400°C.

Iron Chemical Classification

The chemical classification of iron includes:

  • Iron, due to properties like ductility and malleability, finds various applications in industries.
  • Iron easily gets rusted when it comes in contact with moist air.
  • Iron is used as a catalyst in the manufacturing process of ammonia (Haber process).
  • Iron is readily soluble in acids (dilute).

Iron state at room temperature

At room temperature, iron exists in solid form.

Is Iron paramagnetic?

Paramagnetic type of material can get magnetized when placed or comes in contact of magnetic field. Let us check for iron.

The element iron is paramagnetic in nature as its orbitals have unpaired electrons.


Iron is a transition element belonging to group 8 and period 4. It has 4 stable (naturally occurring) isotopes. It is a very important commercial element.

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