What is the atomic mass of chlorine?

In this brief article, we will answer the question, “What is the atomic mass of chlorine?” and provide information on its physical properties, chemical properties, health impacts of exposure to them, environmental impacts as well as its uses.

What is the atomic mass of chlorine?

The atomic mass of chlorine is 35.5. This is the average mass of chlorine with its isotopes. One mole of chlorine would be equal to 35.45 grams.

Why is the atomic mass of chlorine not a whole number?

Chlorine contains 2 isotopes. Chlorine-35 and Chlorine-37 are the two isotopes. In Chlorine-35 there are 17 protons and 18 neutrons. This isotope is most commonly found in nature.

In Chlorine-37, there are 17 protons and 20 neutrons. Chlorine-37 is not found as much as Chlorine-35 in nature. The presence of these isotopes can make the atomic mass 35.5 which is not a whole number.

What are the physical properties of chlorine?

Chlorine appears greenish-yellow in gas form. It is heavier than air. Chlorine can be converted to a liquid form by cooling them. Chlorine contains 17 electrons along with 17 protons. Chlorine can have a very unpleasant and pungent smell.

It has 3 electron shells wherein the first, second, and third electron shells contain 2, 8, and 7 electrons respectively. 

As the outer shell (third shell) also called a valence shell contains 7 electrons, the valency of chlorine is 7. However, chlorine can also have a valency of 1 as it needs only one electron to complete itself.

What are the chemical properties of chlorine?

Chlorine has a high affinity towards electrons. It has a high affinity towards hydrogen too. As a result, it can react with hydrogen in the presence of light to form hydrochloric acid.

As chlorine has a high affinity towards hydrogen, it can interact with other compounds containing hydrogen as well.

Chlorine consists of 2 atoms and thus it is denoted as (Cl₂). Chlorine can react with almost all kinds of molecules. Chlorine has multiple oxidation states which include -1, +1, +3, +7, and +5. Chlorine is a bit soluble in water. In reaction to water, chlorine can form chlorine water. 

What are the health impacts of chlorine exposure?

Chlorine is very volatile and reactive. Exposure to chlorine can occur in the workplace or through air and water. The effects of chlorine on the human body can depend on the length of exposure to chlorine.

Chlorine causes irritation in the eyes, skin, and respiratory system. The effects of breathing chlorine are not known. Some have experienced complications from breathing chlorine whereas others have not.

What can be the environmental impact of chlorine?

When added to water, chlorine can quickly dissolve in them. There are certain instances in which chlorine can escape to air or water.

When chlorine is in water, it can react with inorganic metals. This reaction can result in the formation of organic metals or organic chemicals. Chlorine might not enter groundwater as it is reactive.

Plants and animals exposed to chlorine, do not store them. However, excessive exposure of animals to chlorine can affect their heart, immune system, and respiratory system. Chlorine can affect soil and aquatic organisms at higher levels.

Is chlorine gas harmful?

Yes, high levels of chlorine gas have the capacity to irritate your lungs and cause breathing issues. It can affect both the upper and lower respiratory tract. Chlorine can be easily detected because it has a bleach-like odor.

What are some uses of chlorine?

Chlorine can be commonly added to pools and drinking water. Many people die from water-borne diseases like cholera, hepatitis, or typhoid. 

However, the addition of dichlor and trichlor to the pools can prevent the transmission of pathogens which can result in skin rashes, diarrhea, or athlete’s foot.

Chlorine is also commonly used as a disinfectant in households. Chlorine can also be used to disinfect kitchen and bathroom surfaces. It can help in killing E. Coli, salmonella, and other food-borne germs.

Chlorine can be sprayed on crops to protect them from pests. Chlorine can be a major part of medications. It can reduce cholesterol, arthritis, and allergy. Chlorine can be added to conditioning refrigerants and car batteries. 

Chlorine can be used in building and construction. Chlorine can be added to paints as well. They can be used to prepare bullet-proof vests too.


In this brief article, we have answered the question, “What is the atomic mass of chlorine?” and provided information on its physical properties, chemical properties, health impacts of exposure to them, environmental impacts as well as its uses.



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