Bohr model of Iron Atom-How to draw Iron ( Fe) Bohr Rutherford diagram?

Bohr model describes the visual representation of orbiting electrons around the small nucleus. It used different electron shells such as K, L, M, N…so on. These shells hold a specific number of electrons, the electron shell which is closest to the nucleus has less energy and the electron shell which is farthest from the nucleus has more energy.

Bohr’s diagram is very interesting and easy to draw. Here, we will draw the Bohr model of the Iron atom with some simple steps.

Steps to draw the Bohr Model of Iron atom

1. Find the number of protons, electrons, and neutrons in the Iron

Protons are the positively charged particles and neutrons are the uncharged particles, both these are constituents of the atom nuclei. Electrons are the negatively charged particles that orbit the nucleus of an atom

To find the number of protons an atom contains, just look at its atomic number.

If the atomic number of atom is 45, then proton will also be 45, if atomic number is 46, then proton will also be 46.

So, the atomic number for Iron is 26, hence, the number of protons in the Iron atom is also 26.

Now, to determine the number of neutrons in an atom, use this formula.

⇒ Number of neutrons in atom = Atomic mass of the atom(rounded to the nearest whole number) – Number of proton in an atom

For example, An atom have 33.988 atomic mass and 16 protons.

Then, to find the number of neutron, round the atomic mass to the near whole number, so, atomic mass 33.988 round to 34.

= (34 – 16 protons) = 18 number of neutrons in the atom

Now, To get the number of neutrons in an Iron atom, look at its atomic mass which is 55.84 rounded to 56, and the number of protons in Iron is 26.

∴ Hence, the number of neutrons in Iron atom = (56 – 26) = 30

It should be noted that “The number of electrons in a neutral atom is equal to the number of protons”.

So, the Iron atom is neutral, hence, its number of electrons will be equal to the number of protons which is 26 as we already discussed.

⇒ The number of electrons in an Iron atom = 26

⇒ The number of protons in a Iron atom = 26

⇒ The number of neutrons in a Iron atom = 30

Let’s read in detail – How to find number of protons, electrons, neutrons?

2. Draw the nucleus of an atom

A nucleus is a dense and small region that contains the number of protons and neutrons of an atom.

In this step, we have to draw a small circle that consists of a number of protons and the number of neutrons of a Iron atom.

3. Draw the First electron shell

“An electron shell may be thought of as an orbit followed by electrons around an atom’s nucleus.”

The first electron shell is also called the K-shell, this is the closest shell to the nucleus of an atom and can hold a maximum of two electrons.

As we know, the Iron atom has a total of 26 electrons. So, put two electrons from it, in the first shell, next to each other.

We have successfully drawn the first shell of the Iron atom that can hold 2 electrons. As an Iron atom has a total of 26 electrons, and from 26 electrons we have used two electrons in the first shell.

∴ (26 – 2) = 24 electrons 

Therefore, we are left with 24 electrons, let’s put them in the next shells of the Iron atom.

4. Draw the Second electron shell

The second shell also called the L-shell that can hold a maximum of 8 electrons. This shell is drawn after the first electron shell.

In the second electron shell, the electrons are added one at a time, starting from the top position and then going in a clockwise direction.

In second shell, electrons are added one at a time in clockwise direction as a clock position – 12 o’clock, 3 o’clock, 6 o’clock, 9 o’clock positions.

Once you place the electrons one at a time to each of the four sides(Top – Right – Bottom – Left], start pairing or doubling them.

As we have 24 remaining electrons of an Iron atom, out of which the second shell can hold only a maximum of 8 valence electrons.

Thus, we place the next 8 electrons of the Iron atom in the second shell. Start from the top position and put electrons one at a time, moving in a clockwise direction (Top-Right-Bottom-Left), and finally pair them up.

At this step, out of the 26 electrons of the Iron atom, we have placed 2 electrons in the first shell and 8 electrons in the second shell.

∴ [26 – (2+8)] = 16 electrons.

This means we are now left with 16 electrons. So let’s see how we can assign them their appropriate positions in the next shells of the Iron atom.

5. Draw the Third electron shell

The third electron shell also called the M-shell can accommodate up to 18 electrons. For the elements in the first few periods of the Periodic Table, the third shell holds up to 8 electrons only. But actually, in totality, it has the capacity to hold 18 electrons.

⇒ The third subshell exhibits this capacity of holding ‘up to 18’’ electrons for atomic numbers greater than 20 such as 21, 22, 23, 24 and so on.

⇒ This 18 electron-holding property of the third shell is specifically important for the d-block elements (Scandium to Zinc).

⇒ The M-shell is divided into subshells (s, p, and d). s can hold only 2 electrons. 6 electrons can be placed in the p-subshell. 2+6 =8, so after these 8 electrons, the rest of the electrons can be placed in the d-subshell of the third shell.

So, it is due to the presence of the d-subshell that the third shell can hold more than 8 and up to 18 electrons in total.

⇒ Another rule to keep in mind is that the filling of electrons follows the Aufbau Principle. Electrons are filled diagonally.

After completely filling the s and p subshell of shell number 3, 2 electrons are accommodated in the s-subshell of the fourth shell. Only then the remaining electrons are placed in the 3d subshell of the third shell.

Let’s see how that’s done.

Out of the 16 electrons left of the Iron atom, we place 8 electrons in the third shell, moving in a clockwise manner as we have done for electrons in step 4.

∴ 16 – 8 = 8.

As we already told you, after the 8 electrons in the third shell, we first need to place 2 electrons in the fourth shell and then come back to place the remaining electrons into the third shell again.

Thus, let us place 2 electrons out of the 8 left in the fourth shell first.

6. Draw the Fourth electron shell

Here, we draw the fourth electron shell and put 2 electrons in it. Starting from the top position, put the electrons one at a time while moving in a clockwise direction (Top-Right—Bottom-Left). Here we have only 2 electrons to put in the fourth shell, so one is placed at the top while the other is situated at the right end as shown below.

∴ 8 – 2 = 6.

We are left with 6 electrons so now we will go back and place these 6 electrons into the third shell.

7. Place the remaining electrons back into the Third electron shell

The remaining 6 electrons of Iron are placed into the Third electron shell, again in a clockwise manner. Now, this shell has a total of 14 electrons.

Now, the 3rd shell has a total of 14 electrons.

In this way, finally, you have the Bohr model of the Iron atom that contains 26 protons and 30 neutrons in the nucleus region while a total of 26 electrons circulate around the nucleus in specific orbits called shells.

The first electron shell of Iron has two electrons, there are eight electrons in the second shell, fourteen electrons in the third shell, and two electrons present in the fourth shell of the Iron atom.

Also Read:-

• Scandium Bohr model
• Titanium Bohr model
• Vanadium Bohr model
• Oxygen Bohr model
• Boron Bohr model
• Beryllium Bohr model
• Lithium Bohr model
• Helium Bohr model
• Nitrogen Bohr model
• Fluorine Bohr model
• Neon Bohr model
• Carbon Bohr model
• Sodium Bohr model
• Silicon Bohr model
• Magnesium Bohr model
• Sulfur Bohr model
• Chlorine Bohr model
• Phosphorus Bohr model
• Aluminum Bohr model
• Argon Bohr model
• Potassium Bohr model
• Bromine Bohr model
• Calcium Bohr model
• Silver Bohr model
• Arsenic Bohr model
• Gold Bohr model
• Krypton Bohr model
• Iodine Bohr model
• Copper Bohr model
• Uranium Bohr model
• Nickel Bohr model

Also check :- Bohr model for all elements of Periodic table

Find the Valence electron of Iron through its Bohr diagram

From the Bohr diagram of an atom, we can easily find the number of valence electrons in an atom by looking at its outermost shell.

Now to determine the valence electrons present in the Iron atom, have a quick look at its Bohr diagram.

The Bohr diagram of Iron has four electron shells (K, L, M, N), the K-shell is the innermost shell while the outermost shell is the N-shell.

Generally, the outermost shell of an atom is also called the valence shell. According to that, definition, the electrons present in the N-shell of the Iron atom are its valence electrons.

The outermost shell i.e., N-shell in the Iron Bohr model contains 2 electrons hence the number of valence electrons present in the Iron atom should also be 2. 

An important point to remember is that valence electrons are also defined as the electrons of an atom that can participate in bond formation during a chemical reaction.

And the transition metal (d-block) elements such as Iron (Fe) are famous for their ability to use the electrons present in their 3d sub-shell in addition to the 4s electrons in chemical bonding.

There are 6 electrons present in the 3d subshell of Fe in addition to 2 electrons in its outermost shell. These six 3d electrons can also act as valence electrons hence Iron is actually believed to have a total of 6+2 = 8 valence electrons.

⇒ However, the most probable valency of Iron is +2 and +3 which means the Fe atom is most likely to lose 2 or 3 of its eight valence electrons available to form ferrous (Fe²⁺) and ferric (Fe³⁺) ions while chemical bond formation.

This concept is known as the variable valency concept of transition metals. But it is out of the scope of this article so let’s move forward.

Let’s read in detail – Valence electrons of transition metals

Electron dot diagram of an Iron atom

The electron dot diagram also called Lewis’s structure of an atom represents the total valence electrons present in it.

As there are 8 valence electrons in an atom of Iron (Fe) so there are 8 dots around the Iron atom in its electron dot diagram, as shown below.

The electron configuration of Iron

Iron has an atomic number of 26 and it contains a total number of 26 electrons. From the Bohr model of Iron, we know that it has 2 electrons in the K-shell, 8 electrons in the L-shell, 14 electrons in the M-shell, and 2 electrons in the N-shell.

So based on this electron distribution between the shells, the electronic configuration of the Iron atom is [2, 8, 14, 2].

Or the electronic configuration of Iron is [Ar] 3d⁶ 4s² since it contains a total of 26 electrons.

Also Read:-

• How to write the electron configuration for any atom?

FAQ

Summary

• The Bohr model of Iron (Fe) is drawn with four electron shells, the first shell contains 2 electrons, the second shell contains 8 electrons, the third shell contains 14 electrons and the fourth shell contains 2 electrons.
• The atomic number of Iron is 26. As Iron (Fe) is a neutral atom hence the number of protons and electrons available for its Bohr diagram are equal i.e., 26.
• The number of neutrons for the Bohr diagram of Iron can be found by subtracting the number of protons from the atomic mass (rounded off to the nearest whole number).
• The electron configuration of Iron in terms of the shells is [2,8,14,2] while in the standard form it is [Ar] 3d⁶ 4s².