How Many Valence Electrons Does Iron (Fe) Have?
The 26th element in the periodic table is iron. The 1st element in group 8 is iron and its symbol is ‘Fe’. The elements in groups 3-12 are called transition elements.
The valence electrons are the total number of electrons in the last orbit (shell). But in the case of transition elements, the valence electrons remain in the inner shell (orbit).
The total number of electrons in the last shell and d-subshell after the electron configuration of iron is called the valence electrons of iron. The last shell of iron has two electrons and the d-subshell has a total of six electrons. Therefore, the valence electrons of iron are eight.
The valence electrons determine the element’s properties and participate in forming bonds. Iron participates in the formation of bonds through its valence electrons.
This article discusses how to calculate the number of valence electrons in iron easily. Hopefully, after reading this article you will know in detail about this.
How do you calculate the number of valence electrons in an iron atom?
The valence electrons determine the properties of the element and participate in the formation of bonds. The electrons of the d-orbital participate in the formation of bonds. So, to determine the valence electrons of a transition element, the last shell electrons have to be calculated with the d-orbital electrons.
The valence electrons have to be determined by following a few steps. The electron configuration is one of them. It is not possible to determine the valence electron without electron configuration.
Knowing the electron configuration in the right way, it is very easy to determine the valence electrons of all elements.
The valence electrons of the transition element cannot be determined according to Bohr’s atomic model because the valence electrons of the transition elements are located in the inner shell.
However, the valence electron of the transition element can be easily determined according to the Aufbau principle. Now we will learn how to determine the valence electron of iron(Fe).
Step-1: Determining the total number of electrons in iron
1st we need to know the total number of electrons in the iron atom. To know the number of electrons, you need to know the number of protons in iron. To know the number of protons, you need to know the atomic number of the iron element.
To know the atomic number we need to take the help of a periodic table. It is necessary to know the atomic number of iron elements from the periodic table. The atomic number is the number of protons. Electrons equal to protons are located outside the nucleus.
That is, we can finally say that there are electrons equal to the atomic number in the iron atom. From the periodic table, we see that the atomic number of iron is 26. That is, the iron atom has a total of twenty-six electrons.
Step-2: Need to do electron configuration of iron
Step 2 is very important. In this step, the electrons of iron have to be arranged. The electron configuration shows that the first shell of iron has two electrons, the second shell has eight electrons, the 3rd shell has fourteen electrons and the 4th shell has two electrons. Therefore, the iron electron configuration will be 1s2 2s2 2p6 3s2 3p6 3d6 4s2.
Step 3: Determine the valence shell and calculate the total electrons
The third step is to diagnose the valence shell. The last shell after the electron configuration is called the valence shell. The total number of electrons in a valence shell is called valence electrons.
However, the valence electrons of the transition elements are located in the inner orbit. For the transition element, the valence electrons have to be determined by adding the total electrons of the d-orbital to the electrons in the last orbit of the atom.
The electron configuration shows that the last shell of iron has two electrons and the d-orbital has a total of six electrons. Therefore, the valence electrons of iron are eight.
How many valence electrons does iron ion(Fe2+, Fe3+) have?
The elements that have 1, 2, or 3 electrons in the last shell donate the electrons in the last shell during bond formation. The element that forms bonds by donating electrons is called cation.
There are two types of iron ions. The iron atom exhibits Fe2+ and Fe3+ ions. The iron atom donates two electrons in the 4s orbital to form an iron ion(Fe2+).
Fe – 2e– → Fe2+
Here, the electron configuration of iron ion(Fe2+) is 1s2 2s2 2p6 3s2 3p6 3d6. This electron configuration shows that the iron ion(Fe2+) has three shells and the last shell has fourteen electrons. For this, iron ion(Fe2+) has a total of fourteen valence electrons.
Again, the iron atom donates two electrons in the 4s orbital and an electron in the 3d orbital to convert an iron ion(Fe3+).
Fe – 3e– → Fe3+
Here, the electron configuration of iron ion(Fe3+) is 1s2 2s2 2p6 3s2 3p6 3d5. This electron configuration shows that the iron ion(Fe3+) has three shells and the last shell has thirteen electrons. In this case, the valence electrons of the iron ion(Fe3+) are thirteen.
What is the valency of iron?
The ability of one atom of an element to join another atom during the formation of a molecule is called valency(valence). There are some rules for diagnosing valency.
The number of electrons in an unpaired state in the last shell after the electron configuration of an atom is called the valency of that element.
The oxidation states of iron are +2 and +3. The oxidation state of iron +2 has been used in the iron(II) oxide or ferrous oxide(FeO). The valency of iron in this compound is 2.
On the other hand, The oxidation state of iron +3 has been used in the iron(III) oxide or ferric oxide(Fe2O3). The valency of iron in this compound is 3. The valency and oxidation states depend on the bond formation.