Cl
35.450Chlorine
Klor
Chlorine is a reactive halogen gas with atomic number 17. It is widely used in water disinfection, PVC production, bleach, pharmaceuticals and many chemical manufacturing processes.
17
35.45 g/mol
[Ne] 3s² 3p⁵
2 | 8 | 7
3.16
3.17e-3 g/cm³
-101.5 °C
-34.04 °C
Carl Wilhelm Scheele
Chlorine was discovered by Carl Wilhelm Scheele in 1774. Humphry Davy later recognized it as an element, and its name comes from the Greek word chloros, meaning greenish yellow.
Chlorine-35
Natural abundance: About 75.8%. The most abundant stable isotope of chlorine.Chlorine-37
Natural abundance: About 24.2%. Stable isotope that creates the characteristic M+2 mass spectrum pattern with chlorine compounds.Chlorine-36
Natural abundance: Trace amounts. Half-life: About 301,000 years. Radioactive isotope used in environmental and geological studies.NaCl
Sodium ChlorideCommon salt and major natural source of chloride ions.HCl
Hydrochloric AcidStrong acid used in laboratories, industry and stomach acid chemistry.NaClO
Sodium HypochloriteActive ingredient in many bleach and disinfectant solutions.PVC
Polyvinyl ChlorideMajor chlorine-containing plastic used in pipes, cable insulation and building materials.CaCl₂
Calcium ChlorideUsed for de-icing, drying and dust control.- Disinfection of drinking water and swimming pools
- Production of PVC plastics and many chlorinated chemicals
- Household and industrial bleach through hypochlorite compounds
- Manufacture of pharmaceuticals, solvents, paints and polymers
- Paper and textile bleaching in controlled industrial processes
- Chemical synthesis as an oxidizing and chlorinating agent
Chlorine is essential in the body as chloride ions, which help maintain fluid balance, nerve function and stomach acid. Chlorine gas itself is toxic and must be handled with strict safety controls.
- Chlorine gas is yellow-green and has a sharp, choking smell.
- Chloride ions are common in seawater and in ordinary table salt.
- The two main chlorine isotopes make chlorine-containing molecules easy to recognize in mass spectra.
- Chlorination of drinking water was one of the major public-health advances of the twentieth century.
- Chlorine atoms released from some CFCs can catalytically destroy ozone in the stratosphere.
- Chlorine has atomic number 17 and belongs to group 17, the halogens.
- Its electron configuration is [Ne] 3s² 3p⁵.
- Chlorine commonly forms Cl⁻ by gaining one electron.
- Chlorine reacts with water to form hydrochloric acid and hypochlorous acid, a key disinfecting species.
What is the atomic number of chlorine?
The atomic number of chlorine is 17.
What is the electron configuration of chlorine?
Chlorine has the electron configuration [Ne] 3s² 3p⁵.
Is chlorine a halogen?
Yes. Chlorine is a group 17 halogen.
How does chlorine disinfect water?
Chlorine disinfects water by forming reactive chlorine species such as hypochlorous acid, which help kill microorganisms.
Why is chlorine important in PVC?
PVC, or polyvinyl chloride, is a major chlorine-containing plastic used in pipes, cable insulation and building materials.
What is chlorine used for?
Chlorine is used for water disinfection, PVC production, bleach, pharmaceuticals and chemical manufacturing.