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The Versatility of Chlorine: From Water Purification to Construction and Pharmaceuticals

Chlorine Atom: Electronic Configuration and Properties

When it comes to chemical elements, the electronic configuration plays a vital role in determining its properties. Chlorine, a member of the halogen family, has been a significant component of human civilization for centuries.

In this article, we will explore the electronic configuration of the chlorine atom and its properties.

Electronic Configuration of Chlorine Atom

The unabbreviated electronic configuration of a chlorine atom is

1s2 2s2 2p6 3s2 3p5. This notation gives us insight into the sublevels and the number of electrons present in them.

The numbers written before the letter s and p indicate the energy levels, and the superscript numbers denote the number of electrons. The notation of chlorine electron configuration can be represented by using the noble gas notation as it belongs to the third-period elements.

The electronic configuration of Argon is (1s2, 2s2, 2p6,3s2, 3p6), so we can write the chlorine configuration by substituting Argon’s symbol with “[Ar]”. Thus, the electronic configuration of Chlorine in noble gas notation is “[Ar] 3s2 3p5”.

Chlorine’s ground state electron configuration is the arrangement of electrons in the lowest possible energy level. In this state, the total energy of the system is at the minimum.

The ground state configuration of Chlorine is as follows:

1s2 2s2 2p6 3s2 3p5

However, when the chlorine atom gains energy from an external source like light or heat, it can go into an excited state. The excited state of Chlorine electron configuration is when at least one electron is promoted to an energy level higher than its ground state.

Some of the possible excited states of Chlorine are:

3s1 3p6

3s2 3p4

3s2 3p3 3d1

Placement of Chlorine in Periodic Table

Chlorine is on the 17th group of the periodic table, also called the halogen group. Halogens are known for their high electronegativity, which means they readily accept electrons to form negative ions.

Elements of this family are characterized by their seven valence electrons in the outermost energy level. Chlorine has 17 electrons, and its electronic configuration showcases that the valence shell has 7 electrons.

Physical Properties of Chlorine

Chlorine is a yellow-green gas that has a pungent and choking odor. In nature, it is found as a diatomic molecule (Cl2), where the two chlorine atoms are covalently bonded to each other.

Chlorine is highly reactive, and its malignant properties can be attributed to its high electronegativity and ability to oxidize other substances. Chlorine is a strong oxidizing agent that reacts with organic compounds to form chlorinated hydrocarbons.

These compounds have been useful as solvents, drugs, and pesticides. Chlorine is also used to bleach paper and textile products.

Due to its oxidizing properties, chlorine is also an essential component of chemical purification processes, such as treating water.

Uses of Chlorine

Chlorine is essential in construction, pharmaceuticals, and several other industries. Its ability to kill bacteria has led to its widespread use in water treatment.

In water purification, chlorine acts as a disinfectant agent by reacting with organisms and breaking down harmful chemicals, which may cause waterborne diseases. In the construction industry, chlorine is used in the manufacture of PVC plastic, which is an essential component of pipes and window frames.

PVC plastic is highly durable and resistant to corrosion, which makes it ideal for water management systems. Chlorine’s oxidizing properties also make it a useful chemical in the pharmaceutical industry.

Chlorine is used to manufacture medicines like aspirin and paracetamol. It is also an essential component in the production of pesticides and herbicides.


In this article, we have discussed the electronic configuration and properties of Chlorine. Chlorine’s electron configuration provides us with valuable insights into its properties and behavior.

Chlorine’s high electronegativity and molecular structure give rise to its unique physical and chemical properties. Chlorine’s uses span across industries – from water purification to construction and pharmaceuticals.

Its versatility and utility make it a crucial element for modern human civilization.

3) Chlorine Electron Configuration

Chlorine is a halogen element with atomic number 17. It has 17 electrons arranged in different shells around the nucleus.

To write the electronic configuration of Chlorine, we need to follow the Aufbau principle, Hund’s rule, and the Pauli exclusion principle. The Aufbau principle states that electrons occupy the lowest energy level orbitals first.

In other words, electrons fill up the shells in order of increasing energy. The first shell can hold a maximum of two electrons, the second shell can hold up to eight electrons, the third shell can hold up to eighteen electrons, and so on.

Hund’s rule describes the order in which electrons fill up the subshells of a given energy level. It states that electrons occupy the orbitals singly, with parallel spins, before pairing up.

This is done to minimize the repulsion between electrons and to stabilize the atom. The Pauli exclusion principle states that an orbital can hold a maximum of two electrons with opposite spin.

This principle ensures that no two electrons in an atom can have the exact same set of quantum numbers. Using these principles, we can write the electronic configuration of Chlorine as 1s, 2s, 2p, 3s, 3p.

Here, the first shell (n=1) contains two electrons in the 1s subshell, and the second shell (n=2) has eight electrons in the 2s and 2p subshells. Lastly, the third shell (n=3) has seven electrons in the 3s and 3p subshells.

In excited states, Chlorine can have an electron configuration of 1s, 2s, 2p, 3s, 3p, 3d, which means one electron from 3p has moved to the 3d subshell, leading to the excited state of the Chlorine atom.

4) Ground State Orbital Diagram of Chlorine

The orbital diagram is a pictorial representation of the electronic configuration of an element in which the electrons are placed in boxes or circles that symbolize the orbitals. In the case of Chlorine, we can draw the ground state orbital diagram using Hund’s rule to place the electrons in the subshells.

Starting with the first shell, we can draw two circles to represent the two electrons in the 1s subshell. Similarly, we can draw the 2s and 2p subshells with a total of eight electrons.

Finally, we can draw the third shell with seven electrons; three paired electrons in the 3s subshell and four unpaired electrons in the 3p subshell. According to Hund’s rule, we place each electron in a different 3p orbital with parallel spin before pairing them up.

From the orbital diagram, it is clear that Chlorine has a half-filled 3p subshell, which is more stable than other configurations. This stability can be attributed to the exchange energy of electrons spinning in parallel directions, as they maintain a minimum separation and achieve a lower total energy.


The electronic configuration and orbital diagram of Chlorine provide significant insight into its properties and behavior. The Aufbau principle, Hund’s rule, and the Pauli exclusion principle guide us in determining the arrangement of electrons in different shells and subshells.

The electron configuration confirms that Chlorine belongs to the halogen family, which has a characteristic 7 electrons in their outermost valence shell. The orbital diagram reveals the partially filled 3p subshell of Chlorine, which imparts remarkable stability to it.

Understanding the electronic configuration and orbital diagram of Chlorine can help to comprehend its chemical reactivity and applications. 5)


Chlorine is a versatile and essential chemical element that plays a vital role in human civilization. With its significant properties, it has become a ubiquitous element in our lives, spanning across different sectors and industries.

Let us now investigate how Chlorine is present in everyday life applications. Sodium Chloride: Common Salt

Sodium Chloride is a compound of Chlorine and Sodium which has an important role in our diet and health.

It is popularly known as common salt and is used to enhance the taste and flavor of foods. Apart from that, it also maintains the balance of fluids in our body and helps in muscle relaxation.

Sodium Chloride is also used as a preservative to prevent food spoilage.

Water Purification

Chlorine is extensively used in water purification to disinfect water from harmful bacteria and viruses. Municipal water treatment plants typically add Chlorine in the form of Sodium Hypochlorite, Calcium Hypochlorite, or Chlorine gas to water supply systems.

Chlorine reacts with the microorganisms in the water and oxidizes organic compounds to kill harmful pathogens. However, excessive use of Chlorine in water can lead to health hazards, as it may cause respiratory problems, skin irritations, and other side effects.

Construction Industry

In the construction industry, Chlorine has several significant uses. It is used to manufacture PVC plastic, which is an essential component used in pipes, wiring insulation, window frames, wall coverings, and flooring.

PVC plastic is highly durable and resistant to corrosion, which makes it ideal for water management systems.

Chemical Industry

The chemical industry relies heavily on Chlorine as a raw material for the production of many essential chemicals. Chlorine is used to produce the chlorinated hydrocarbons, which are used as solvents, pesticides, and herbicides.

Chlorine is also an essential component in the production of pharmaceuticals such as aspirin and paracetamol. The chemical industry also utilizes Chlorine to create bleaching powders and oxidizing agents that are used in industrial processes.


Uses of Chlorine

Chlorine has several other uses, such as in the production of high-performance elastomers, as a catalyst in chemical reactions, and as an oxidizing agent in the production of bromine. It is used in the production of polyurethane foams found in car seats and insulation material.

In the textile industry, Chlorine is used to bleach fabrics and remove stains.


Chlorine is a remarkable element with multiple uses and applications in various industries. From water purification to the construction and chemical industries, Chlorine plays a vital role in our modern-day civilization.

Despite the significant benefits it provides, it is essential to note that Chlorine usage must be regulated to prevent adverse health and environmental effects. As a society, we must adopt safe and responsible methods of utilizing Chlorine and its derivatives to realize its full potential.

Chlorine, with its electronic configuration and unique properties, is a crucial element in various industries and applications. From its role in water purification to its use in construction and chemical production, Chlorine’s versatility and effectiveness cannot be overstated.

However, it is crucial to regulate and use Chlorine responsibly to minimize its potential health and environmental risks. Understanding the electronic configuration and properties of Chlorine provides valuable insights into its reactivity and applications.

So, next time you enjoy salt on your food, drink clean and safe water, or admire the durability of PVC pipes, remember the significant role Chlorine plays in our daily lives. FAQs:

1) How does Chlorine purify water?

Chlorine acts as a disinfectant by reacting with microorganisms and oxidizing organic compounds in water, effectively killing harmful pathogens. 2) Is Chlorine safe to use in water purification?

When used in regulated amounts, Chlorine is an effective and safe method of water purification. However, excessive use can have health hazards and should be avoided.

3) What are the uses of Chlorine in the construction industry? Chlorine is used in the production of PVC plastic, which is highly durable and corrosion-resistant, making it ideal for pipes, window frames, and other construction materials.

4) Why is Chlorine used in the chemical industry? Chlorine is a key raw material in the production of chlorinated hydrocarbons, solvents, pesticides, herbicides, and pharmaceuticals.

5) What precautions should be taken when using Chlorine? Proper handling, storage, and dosage of Chlorine are essential for ensuring safety.

Excessive exposure or improper usage can lead to health and environmental risks. 6) Are there alternative methods for water purification besides Chlorine?

Yes, there are alternative methods such as UV irradiation, ozonation, and advanced filtration techniques. These methods may be used in conjunction with or as alternatives to Chlorine depending on specific needs and circumstances.

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