Chlorine Facts

Chlorine is a chemical element with the symbol Cl and atomic number 17.

It’s greenish-yellow color gas that is really highly reactive and toxic.

It’s used in so many different ways, including to make bleach and other cleaning products. Some types of medicine use it to kill bacteria.

Chlorine is dangerous if not handled properly.

You can get really very sick if you breathe in too much chlorine gas, and it can cause irritation to your eyes and skin.

Atomic Number17
Element NameChlorine
Atomic Mass35.45 g/mol

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Chlorine Facts for Kids

  • Chlorine is a chemical element with the symbol Cl and atomic number 17.
  • It is a greenish-yellow gas that is highly reactive and toxic.
  • Chlorine is used in bleach and other cleaning products.
  • It is also used in some types of medicine to kill bacteria and other germs.
  • Chlorine is very dangerous if not handled properly.
  • It is important to always follow the safety rules when working with Chlorine.

The basic properties of Chlorine

Atomic number

Chlorine has an atomic number of 17, which means that it has 17 protons in the nucleus of each of its atoms.


The symbol for Chlorine is Cl. This symbol is derived from the Latin name for the element, “chlorum,” which means “greenish-yellow.”


The element chlorine is classified as a halogen, along with fluorine, bromine, iodine, and astatine. Halogens are reactive and can form compounds with other elements.

Atomic mass

The atomic mass of Chlorine is 35.45 AMU (atomic mass units), which is the average mass of all the isotopes of Chlorine.

Physical properties

Chlorine is a greenish-yellow gas at room temperature. You need to be careful because large amounts of it are highly toxic if inhaled. Also, it can be easily combined with some other elements to form compounds.

Chemical properties

In the periodic table, Chlorine is the most electronegative element, which means it attracts electrons very strongly. Due to this property, it forms compounds easily with other elements. It is also the lightest halogen, making it highly reactive and able to form compounds.

The occurrence of Chlorine in the Earth’s crust

Chlorine does not occur naturally as a free element.

Instead, it exists in the Earth’s crust in the form of compounds with other elements, such as sodium and potassium.

Halite, also known as rock salt, is the most common source of Chlorine. It’s also found in sylvite and carnallite.

Saltwater and seawater also contain it.

You’ll also need to know that in the presence of other elements, Chlorine forms chlorides. Salt (sodium chloride) and potassium chloride are other common chlorides of Chlorine.

The uses of Chlorine

Some common uses of Chlorine include:


Bleach is a very strong and effective disinfectant. It’s used to kill germs and bacteria in homes and even hospitals, another interesting way it is used is to whiten clothes and other materials.


Disinfectants are commonly used in hospitals, schools, and other public places to help prevent the spread of illness and disease.

Water treatment

Chlorine is used in the treatment of drinking water to kill bacteria and other harmful organisms. I’m sure you know already that’s it’s also used in swimming pools and other sources of water to make sure the water clean and safe for use.

Industrial processes

It’s used in the production of plastics, solvents, and other chemicals. It is also used in the production of metals, amazingly they also but is in aluminum and steel, and it helps improve the overall strength and other properties.

The potential dangers

Any exposure to large amounts of Chlorine can be very Hazardous.

If you somehow inhale this gas, it can really cause irritation to your nose, eyes and throat. This then leads to difficulty breathing, coughing, and even chest pain.

You really don’t want to ingest it either because it can cause burning of the mouth, throat, and stomach, and that could use you more issues like vomiting and diarrhea.

The last thing you want is any chemical burns that will cause pain and could also lead to other damage to the skin and eyes.

Important to seek medical attention immediately if you have any large levels of exposure to Chlorine.

What is the role of Chlorine in industry?

Chlorine is used in so many different ways in industry. Here is a list of everything we found

  1. Production of plastics
  2. Production of solvents
  3. Production of other chemicals
  4. Production of metals such as aluminum and steel
  5. Improving the strength and other properties of metals
  6. Production of pesticides and herbicides
  7. Disinfection and sterilization of equipment and facilities
  8. Purification of drinking water and wastewater
  9. Processing of food and beverages
  10. Manufacturing of textiles and other materials
  11. Bleaching of wood pulp and other materials for paper production
  12. Production of rubber and other polymers
  13. Production of pharmaceuticals and other medical compounds
  14. Production of dyes and other chemicals for the textile industry
  15. Production of inorganic and organic compounds for use in scientific research and industry
  16. Production of chemicals for use in agriculture and horticulture
  17. Production of chemicals for use in personal care and cosmetic products
  18. Production of chemicals for use in household cleaning products
  19. Production of chemicals for use in industrial coatings and adhesives
  20. Production of chemicals for use in fire retardants and other safety products.

How was Chlorine discovered?

It was discovered by a brilliant Swedish chemist called Carl Wilhelm Scheele in 1774.

During his studies, he was working with a mineral called pyrolusite, which is a type of manganese dioxide, when he isolated the element chlorine

When he isolates the element by mixing an acidic solution of manganese dioxide with hydrochloric acid, a compound that contains the element chlorine, it was the greenish-yellow gas that helped Scheele recognize it as the element chlorine.

Scheele decided to name the element “chlorine” after the Greek word “chloros,” which means “greenish-yellow.” Simply when you think about it, isn’t it?

He also wrote about his discovery in a paper that was published in 1777.