How many valence electrons does chlorine have?

What is the valency of chlorine(Cl) Valence electrons

Chlorine is element number 17 on the periodic table. He is also part of group-17. Its symbol is “Cl”. Through its valence electrons, chlorine forms bonds. This article will discuss the valence elements for chlorine in detail.

The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a pale green gas at standard temperature and pressure. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the pauling scale, behind only oxygen and fluorine.

chlorine element


Because chlorine can combine with almost all elements, it is not found in nature free of it. Carl Wilhelm Scheele, a Swedish scientist and chemist, was the first to produce chlorine. He combined the mineral pyrolusite (MnO 2 ) with hydrochloric acid (HCl) in 1774. Scheele believed that the gas he produced contained oxygen. However, it was shown to be a distinct element by Sir Humphry Davy in 1810. Electrolysis of aqueous sodium chloride (NaCl) is the primary method of producing most chlorine today.

Chlorine antiseptic is often used in drinking water treatment and swimming pool maintenance. Many industrial processes use large amounts of chlorine, including the production of paper and plastic products.

Chlorine is found in nature primarily as the chloride ion cl-. This ion is formed when the element chlorine gains one electron to form an negatively charged ion, or anion. The chloride ion is found in abundance in seawater and many minerals such as rock salt, or halite. The name «chlorine» is derived from greek word chloros, meaning «greenish-yellow.» this refers to chlorine’s characteristic color when it is a gas at room temperature and pressure. When chilled or compressed, chlorine becomes a reddish-brown liquid. At very high temperatures, it turns back into a greenish-yellow gas.


It kills bacteria and is used as a disinfectant. It is used to disinfect swimming pools and drinking water. It can also be used to make hundreds of consumer products, including paper, paints, textiles, and insecticides. In the past, chlorine was used to make anesthetics such as chloroform and carbon tetrachloride as a dry cleaning solvent. Both chemicals can cause liver damage and are now strictly controlled.

Organic chemistry is another important application of chlorine. It is used in substitution reactions and as an oxidizing agent. At some point in the manufacturing process, 85% of pharmaceutical products contain chlorine or one of its compounds. PVC is made from about 20% of the chlorine produced. This versatile plastic is used for window frames, car interiors, and electrical wiring insulation. It can also be used to make vinyl flooring.

Chlorine’s position in the periodic table

Position of Chlorine in the periodic table

Biological role

Essential to our existence, the chloride ion plays a vital role. It is mainly found in cell fluids as a negative ion that balances the positive ions (mainly potassium). It can also be found in extracellular fluid (eg, blood) to balance the positive (mainly sodium).

Chlorine is found in nearly every molecule in the body, making it essential to life. It is one of the basic elements of the universe and is essential to the proper functioning of cells.

Chlorine is a highly reactive element that forms strong bonds with other atoms. This makes it an important part of many biochemical processes, including those involved in digestion, metabolism, and respiration. Chlorine also plays a role in cell signaling and regulation.

The element is also important for maintaining fluid balance in the body and for preventing infection. Chlorine is produced naturally by the body, but can also be obtained from food and water.

While chlorine is necessary for life, too much of it can be harmful. Exposure to high levels of chlorine can irritate the skin and eyes, and cause difficulty breathing. In severe cases, it can lead to death.

Chlorine has health effects

Although chlorine is essential to many of the things we take for granted, it can also be dangerous. Chlorine exposure can cause a number of health problems, including:

  • respiratory problems: chlorine can irritate the respiratory system and cause coughing, wheezing and shortness of breath. Inhaling high levels of chlorine can lead to a build-up of fluid in the lungs (pulmonary edema), which can be fatal.
  • skin problems: chlorine can cause skin irritation, redness and rashes. Prolonged exposure can increase the risk of developing cancerous lesions on the skin.
  • gastrointestinal problems: chlorinated water can irritate the stomach and intestines, leading to nausea, vomiting and diarrhea. In severe cases, it may even lead to death from dehydration or from electrolyte imbalances caused by vomiting and diarrhea.
  • eye problems: chlorine can irritate the eyes, causing redness, watering and burning sensations. Prolonged exposure can damage the cornea (the clear outer layer of the eye).
  • neurological effects: exposure to high levels of chlorine can damage the nervous system and cause seizures, coma and even death.


Two stable isotopes of chlorine are Cl-35 and Cl-337. The mixture of these isotopes is what you will find in nature as chlorine.

atomic number17
atomic weight35,446 to 35,457
Boiling point-34°C (-29°F)
melting point-103°C (-153°F)
density (1 atm, 0 °C or 32 °F)3.214 g/liter (0.429 oz/gal)
oxidation states−1, +1, +3, +5, +7
electronic configuration1 second 2 2 second 2 2 pg 6 3 pg 2 3 pg 5

Natural abundance

Chlorine is a naturally occurring element that is estimated to make up about 0.045% of the earth’s crust. It is a member of the halogen group of elements, which includes fluorine, bromine, and iodine. Chlorine is found in both combined and uncombined states in nature. The most common compound is sodium chloride, or common salt.

Chlorine was first isolated in 1774 by swedish chemist carl wilhelm scheele. He produced it by reacting hydrochloric acid with manganese dioxide. However, it was english chemist humphry davy who gave chlorine its name in 1810 when he succeeded in isolating it as a gas by electrolysis of potassium chlorate.

The element’s distinctive greenish-yellow color and pungent odor led to its use in world war i as a chemical weapon known as chlorine gas. Fortunately, it has since been replaced by more sophisticated chemical weapons. Today, chlorine is widely used in industry for a variety of purposes, including the production of paper pulp, plastics, dyes, textiles, medicines, and disinfectants such as bleach.

Although chlorine is essential for life and has many uses, it can also be dangerous. For example, chlorinated water can cause birth defects if pregnant women drink too much of it. In addition, exposure to high concentrations of chlorine gas can irritate the eyes and lungs and even be fatal. Therefore, it is important to handle this element with care.

The environmental effects of chlorine

When mixed with water, the chlorine will dissolve. Under certain conditions, it can escape from the water and get into the air. The environment bears the brunt of chlorine released directly into the atmosphere and surface water. Chlorine reacts with other chemicals once it is in the air or water. Reacts with water to produce chloride salts.

What are the valence elements of chlorine?

The nonmetal element chlorine can also be called the halogen element. The total number of electrons in the last orbit of a shell (valence electrons) is called valence electrons. Valence electrons are the total number of electrons within the shell that have been formed by the chlorine configuration. The properties of an element are determined by the valence electrons. They also participate in the training bonds.

What are the valence electrons of chlorine?

What number of electrons, neutrons, and protons does chlorine have?

The nucleus can be found in the middle of an atom. The nucleus contains protons and neutrons. The atomic number of chlorine is 17. The number of protons in a substance is called the atomic number. The number of protons found in chlorine is 17. The nucleus contains a shell of electrons that is equal to the protons. A chlorine atom can have a total number of 17 electrons.

The difference between the number of atomic masses and the number of atoms is what determines the number of neutrons within an element. This means that number of neutrons (n) = atomic mass (A) + atomic number (Z).

We know that the atomic quantity of chlorine is 17 and that its atomic mass is 35 (35.45u). Neutron (n) = 35 – 17 = 18. Therefore, the number of neutrons found in chlorine (Cl) is 18.

Valence is the ability of an atom of a chemical element to form a certain number of chemical bonds with other atoms. It takes values ​​from 1 to 8 and cannot be equal to 0. It is determined by the number of electrons of an atom spent to form chemical bonds with another atom. The valence is a real value. Numerical valence values ​​are indicated by Roman numerals (I, II, III, IV, V, VI, VII, VIII).

How can you find the number of valence neutrons in a chlorophyll atom?

Here are the steps to determine the valence electrons. One of them is the electronic configuration. Without an electron configuration, it is impossible to determine the valence of an electron. It is easy to determine the electronic configuration of all the elements.

However, it is possible to identify the valence electrons by placing the electrons according to Bohr’s principle. Now we will learn to identify the valence electron of chlorine.

The terms ” degree of oxidation ” and ” valency ” may not be the same, but they are numerically nearly identical. The conditional charge of the atom of an atom is called the oxidation state. It can be positive or negative. Valence refers to the ability of an atom to form bonds. It cannot have a negative value.

Calculation of the total number of electrons in chlorine

First, we must know the number of electrons present in the chlorine atom. You need to know how many protons are in chlorine to determine the number of electrons. To find the number of protons in chlorine, you must also know its atomic number.

A periodic table is required to determine the atomic number. The periodic table contains the atomic numbers of the elements chlorine. The number of protons is called the atomic number. The nucleus also contains electrons that are the same as protons.

This means that we can now say that the number of electrons in the chlorine atom is equal to its atomic number. The atomic number of chlorine is 17 according to the periodic table. This means that the total number of electrons in a chlorine atom is 17.

  1.  Valence is a numerical characteristic of the ability of atoms of a given element to bond with other atoms.
  2. The valence of hydrogen is constant and equal to one.
  3. The valence of oxygen is also constant and equal to two.
  4. The valence of most other elements is not constant. It can be determined by the formulas of its binary compounds with hydrogen or oxygen.

You will need to perform the electronic configuration of chlorine.

Important Step 2 This step involves ordering the electrons of the chloride. The electron configuration of chlorine is that there are two electrons inside the K shell, eight inside the L shell, and seven inside the M shell. The electron configuration of chlorine shows that the first shell contains two electrons, while the second shell has eight electrons. The third shell contains seven electrons. Across the suborbital, the electronic configuration of chlorine is 1s 2  2s 2  2p 6  3s 2  3p 5 .

Calculate the total electrons and determine the valence shell.

Chlorine atoms have 17 electrons around the nucleus, arranged in shells of 2, 8, 7 electrons. The valence shell is the outermost shell; for chlorine, this is the 3rd shell (2+8+7=17). The valence shell determines how chemically reactive an atom is — atoms with full or half-full valence shells are less reactive, while atoms with empty or almost-empty valence shells are more reactive. In general, reactivity increases as you go down the periodic table because elements at the bottom have larger atomic radii and thus weaker nuclear attraction forces; chlorine is an exception to this trend because of its high electronegativity.

Formation of chlorine compounds (Cl)

Through its valence electron, chlorine (Cl) is involved in bond formation. These valence electrons are involved in bond formation with other elements. The electronic configuration of sodium indicates that the valence elements of sodium exist as one. The sodium atom gives up its valence electrons and the chlorine receives them.

Compound formation of chlorine(Cl)

In this way, the electronic configurations of chlorine and sodium are acquired. Through the exchange of electrons, sodium and chlorine atoms form sodium chloride (NaCl). The ionic bond is sodium chloride (NaCl).

How many valence electrons does the chlorine ion (Cl ) have?

During bond formation, elements with 5, 6, or 7 electrons receive electrons from the shell that contains them. Anions are elements that have electrons and can form bonds. The last layer of chlorine is affected by an electron during bond formation and becomes a chlorine ion (Cl ). This is the reason why chlorine is called an anion element.

How many valence electrons does chlorine ion(Cl–) have

The electronic configuration of the chlorine ion (Cl ), is 1s 2  2s 2  2p 6  3s 2  3p 6 .  The electronic configuration of chlorine ions (Cl ), shows that there are three shells for the chlorine ion (Cl ), and that the third shell contains eight electrons. This electron configuration indicates that the chlorine ion is now and has the electron configuration of argon. In this case, the valence of chlorine ions is -1. The valence electrons for chlorine ions (Cl ) have eight electrons in the shell containing the last shell of chlorine ions.

What is the valence of chlorine (Cl)?

Valency (or valency) is the ability of an atom of an element to bond with another atom in the formation of a molecule. Valence is the number of unpaired electrons found in the last orbit of an element. In the ground state, the correct electron configuration for chlorine (Cl) will be 1s 2  2s 2  2p 6  3s 2  3p x 2  3p y 2  3p z 1 .

This electronic configuration indicates that the last chlorine atom has an unpaired electron (3p 1 ). Excitation can change the oxidation states of chlorine. The oxidation states of chlorine are -1 to +1, +2, +3, +4, +5, +6, +7.

What is the valence of chlorine(Cl)

The valence of chlorine is therefore 1.


  • The third most abundant element in Earth’s oceans is chlorine.
  • Sodium chloride or table salt is the most common natural chlorine compound.
  • Chlorine atoms make up about 1.9% of the mass of the oceans.
  • Chlorine is the 21st most abundant element in Earth’s soil.
  • The chemical weapon of choice was chlorine gas, which was used in the First World War.
  • Chlorine in containers can be detected using ammonia.
  • Electrolysis of water containing dissolved sodium chloride (salt water) is used to produce most chlorine gas for industry.
  • The chlorine will react with the ammonia and create a white cloud over the leak.


  • Levitin, H; Branscome, W; Epstein, F.H. (December 1958). “The pathogenesis of hypochloremia in respiratory acidosis”. J.Clin. invest _
  • Henry M. Leicester, Herbert S. Klickstein, A Sourcebook in Chemistry, 1400-1900., (1969) Harvard University Press.
  • West, Robert (1984). CRC, Handbook of Chemistry and Physics . Boca Raton, Florida: Chemical Rubber Company Publishing.
  • Antoine Lavoisier, Memoirs of the Royal Academy of Sciences 1783.
Alexander Stephenson

Candidate of Chemical Sciences, editor-in-chief of Lecturer at several international online schools, member of the jury of chemistry competitions and author of scientific articles.

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