Diagram, Steps To Draw The Chlorine Bohr Model

Chlorine belongs to the periodic table’s group 17. It is a halogen element that exists in the form of a greenish-yellow gas. It has a caustic and poisonous character. It is found in the form of sodium chloride in saltwater. Carnallite, kainite, sylvite, and other chlorine-containing minerals are examples.

Free chlorine can also be found in volcanic gases. Chlorine is used for sanitization, disinfection, and antisepsis purposes. During World War I, chlorine gas was also utilised as a weapon.

Welcome, I’m always happy to share chemistry-related information. If you’re interested in the element chlorine, this tutorial will show you how to build a Bohr diagram using a step-by-step instruction.

Keep reading this article to the very end for knowing how to build a Bohr diagram of elemental chlorine in a simplistic approach. So, let’s begin our debate without any delay.

Chlorine Bohr Model

Niel Bohr presented the Bohr-Rutherford model in 1913. The initial Rutherford model was unable to explain some features exhibited by various atoms, so Bohr made changes to the existing model and proposed the final theory, which is still believed to be highly accurate.

The Bohr model of an atom is a visual representation of an element’s atomic structure, showing all of the atomic species, such as protons, neutrons, and electrons.

To understanding the Bohr-Rutherford model, we must first understand a few key words, which are stated below:

• Atomic nucleus: The nucleus is the atom’s centre and has a positive charge due to the presence of protons. It contains protons and neutrons and is located at the heart of the atom.

• Neutrons: These are charge-neutral atomic species found within the nucleus of the atom. Neutrons are usually denoted by the letter n°.

• Protons: These are positively charged particles that are also found inside the nucleus. The sign p+ is used to represent protons.

• Electrons: Outside of the nucleus, electrons are the only atomic particles. Electrons move in a specific path around the nucleus, unlike protons and neutrons, which remain stationary inside the nucleus.

They have a negative charge and are spread throughout the nucleus based on their energy level.

• Shells: A shell or orbit is the circular path that electrons traverse around the nucleus.

Each shell can only hold a given amount of electrons with a specific energy. Because each shell’s energy is constant, these are referred to as energy levels.

The shells are called K, L, M, N, etc., according to the Bohr model, or 1, 2, 3, 4, etc. As the energy grows in the same direction as the number increases away from the nucleus. The ground state describes electrons in the shell nearest to the nucleus that have the lowest energy.

When electrons acquire energy, they are allowed to leap from lower to higher energy levels, and when they release energy, they are allowed to descend from higher to lower energy levels.

The valence shell refers to an atom’s outermost energy level or shell. Chemical bonding occurs when two or more atoms of the same or different elements share electrons in the valence shell.

There are 18 neutrons, 17 protons, and 17 electrons in a chlorine atom. The electrons are arranged in K, L, and M shells around the nucleus.

Sodium AtomValue
No. of Proton17
No. of Neutron18
Number of Electrons17
Number of shells3
Number of electrons in first (K) shell2
Number of electrons in second (L) shell8
Number of electrons in third (M) shell7
Number of valence electrons7

Drawing the Bohr Chlorine Model

Chlorine is a halogen element that belongs to the periodic table’s group 17.

The following is the information that we can obtain from the above-mentioned Chlorine box:

• Chlorine has an atomic number of 17.

• Chlorine has the electronic configuration [Ne] 3s23p6.

• Chlorine’s chemical symbol is Cl.

• Chlorine has an atomic mass of 35.353.

To create a Bohr model of chlorine, we must first determine the atomic species that make up this atom. Let’s start by figuring out how many protons are in chlorine.

The atomic number of any atom is equal to the number of protons in that atom.

The atomic number of a chlorine atom is 17 in this example.

As a result, the number of protons = atomic number = 17 for the chlorine atom.

Now we’ll figure out how many neutrons there are in a chlorine atom.

The number of neutrons present in the nucleus of every atom can be calculated using the following formula:

Atomic mass (rounded up to the closest full number) – number of protons = number of neutrons

The atomic mass of the chlorine atom is 35.353, as shown in the chlorine box above.

We get 35 when we round it up to the nearest whole number.

Now, use the following formula to enter the values:

In a chlorine atom, the number of neutrons is 35 – 17 = 18.

We may sketch the nucleus of a chlorine atom by combining the above numbers because protons and neutrons are present in the nucleus of an atom.

Protons are represented by p+, and neutrons are represented by n° in the diagram above.

We must now determine the number of electrons in the atom in order to complete the Bohr model of chlorine.

The number of electrons in any atom is always equal to that atom’s atomic number.

As a result, when it comes to chlorine atoms,

The amount of electrons equals the atomic number of chlorine, which is 17

Moving on to the following stage, we must now place these electrons in their appropriate energy levels.

To do so, we must first recognise that each shell has a finite capacity for electrons.

2n2 is the maximum number of electrons that can be accommodated in a given shell.

The number of shells is denoted by n in this expression.

We’ll now determine the number of electrons in each shell of the chlorine atom one by one.

The maximum number of electrons in the K shell of a chlorine atom is 2 (1)2 = 2.

The atom looks like this once these two electrons are added to the first shell:

To add the second shell to the atom, we must first figure out how many electrons it can hold.

For the L shell of a chlorine atom, the maximum number of electrons is 2 (2)2 = 8.

As a result, the L shell can hold up to 8 electrons.

However, one crucial aspect to note at this time is that electrons are always added in groups of four in a clockwise orientation to any shell other than the K shell. The initial four electrons in a shell are positioned at a 90° angle to one another. As the number of electrons in a shell grows, this angle decreases.

So, for the L shell of the chlorine atom, we’ll add four electrons first, then sketch the atom as follows:

The remaining four electrons are now introduced to the chlorine atom’s L shell in a clockwise direction.

The chlorine atom is now represented as: after adding all eight electrons to the L shell

After that, we’re left with seven additional electrons, which will be accommodated in the M shell.

We’ll start by calculating the maximum number of electrons that the M shell can hold:

The maximum number of electrons in a chlorine atom’s M shell is 2 (3)2 = 18.

As a result, the M shell can have up to 18 electrons.

Because we only have 7 electrons remaining, we’ll start by adding four electrons clockwise. The chlorine atom now has the following shape:


Finally, all seven electrons are added to the shell, and the result is as follows:

As a result, the final Bohr model of the chlorine atom has 18 neutrons and 17 protons in the nucleus, and 17 electrons in the K, L, and M shells revolving in the group of 2, 8, and 7, respectively.

Using the Bohr Model to Deduce Lewis Structure

The Lewis structure of an atom is a graphical representation of the valence electrons present in the atom.

The Lewis structures are also known as electron dot diagrams because the atoms are represented by their chemical symbol and the electrons are depicted as dots.

The M shell, which includes 7 electrons, is the outermost shell of the chlorine atom, as detailed in the previous section.

These are the chlorine atom’s valence electrons. As a result, the Lewis structure for the chlorine atom is as follows:

Chlorine’s Characteristics

The following are some of the most important features of chlorine:

• Chlorine is a halogen element that is non-metal.

• It’s a highly reactive element that exists at room temperature as a greenish-yellow gas.

• Chlorine has melting and boiling points of -103°C and -35°C, respectively.

• The density of chlorine is 3.214 gm/L at 1 atm pressure and 0°C temperature.

• It is a strongly electronegative element with several oxidation states, including -1, +1, +3, +5, and +7.


The chlorine atom is made up of 17 protons, 17 electrons, and 18 neutrons, according to the Bohr model.

The nucleus contains neutrons and protons, while electrons orbit the nucleus in precise circular routes called shells.

The number of protons in an atom, as well as the number of electrons in that atom, is always equal to that atom’s atomic number.

The formula for calculating the number of neutrons is:

Atomic mass (rounded up to the closest whole number) – number of neutrons

The total number of protons

The K, L, and M shells in the Bohr model of chlorine contain 2, 8, and 7 electrons, respectively.

The formula 2n2 gives the maximum number of electrons that may be held in a shell, where n is the number of shells.

Read more: Is HCN a Potassium Hydroxide?

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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