Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
chlorine
References & Edit History Quick Facts & Related Topics
Images
A labeled diagram of the chlorine element from the periodic table shows its atomic number 17, symbol Cl, electron configuration, and atomic weight range. The box is shaded green to indicate chlorine is a halogen, with icons for orthorhombic crystal structure, gas state at room temperature, and strong acidity. A key explains the icons and colors used. chlorine Diagram showing the formation of an ionic bond between sodium (Na) and chlorine (Cl) atoms. Sodium loses an electron to become Na+, chlorine gains an electron to become Cl-, resulting in sodium chloride (NaCl), or table salt. Dead Sea Explore an interactive periodic table of the elements A scientific graph plots average nuclear binding energy per nucleon (in MeV) against atomic mass number, showing a sharp rise at low mass numbers, peaking near iron (Fe), then gradually declining for heavier elements. Key isotopes are labeled along the curve. Figure 13: Transformations of chlorine compounds in the atmosphere. Diagram showing the chemical reaction where methane (CH4) and chlorine (Cl2) combine to produce chloromethane (CH3Cl) and hydrogen chloride (HCl), with molecular structures and labels.
At a Glance
default image
chlorine summary
Quizzes
Concept artwork on the periodic table of elements.
118 Names and Symbols of the Periodic Table Quiz
Periodic Table of the elements concept image (chemistry)
Facts You Should Know: The Periodic Table Quiz
Related Questions

chlorine: References & Edit History

Article Contributors

Primary Contributors

  • The Editors of Encyclopaedia Britannica
    Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.

Other Encyclopedia Britannica Contributors

Article History

Type Description Contributor Date
Modified link of Web site: Centers for Disease Control and Prevention - Chlorine. Oct 22, 2026
Add new Web site: GOV.UK - Chlorine: general information. Jul 31, 2026
Add new Web site: Australian Government - Department of Climate Change, Energy, the Environment and Water - Chlorine and compounds. Jan 22, 2026
Add new Web site: Respiratory Research - The influence of chlorine in indoor swimming pools on the composition of breathing phase of professional swimmers. Oct 16, 2025
Add new Web site: CAMEO Chemicals - Chlorine. Dec 10, 2024
Add new Web site: United States Enviromental Protection Agency - Chlorine. Aug 21, 2024
Add new Web site: WebMD - What to Know About Chlorine. Apr 02, 2024
Media added. Feb 25, 2024
Add new Web site: Chemical Safety Facts.org - Chlorine. Jan 05, 2024
Add new Web site: The New york State - Department of Health - The Facts About Chlorine. Aug 27, 2023
Add new Web site: Chemistry LibreTexts - Chemistry of Chlorine. Jun 22, 2023
Add new Web site: Centers for Disease Control and Prevention - Chlorine. May 11, 2023
Add new Web site: The Essential Chemical Industry - online - Chlorine. Mar 13, 2023
Add new Web site: Live Science - Facts About Chlorine. Feb 03, 2023
Add new Web site: National Center for Biotechnology Information - Toxicological Profile for Chlorine. Nov 17, 2022
Add new Web site: The Periodic Table - The Element Chlorine. Mar 07, 2021
Added illustration of sodium chloride. Nov 11, 2020
Changed atomic weight from β€œ35.453” to β€œ35.446 to 35.457.” Oct 29, 2020
Added cross-references. Sep 22, 2017
Add new Web site: Jefferson Lab - The Element Chlorine. Dec 16, 2013
Add new Web site: The Virtual Chembook of Elmhurst College - Chlorine. Dec 16, 2013
Add new Web site: Jefferson Lab - Chlorine. Dec 16, 2013
Add new Web site: Royal Society of Chemistry - Chlorine. Dec 13, 2013
Add new Web site: Chemicool - Chlorine. Dec 13, 2013
Add new Web site: Spartacus Educational - Chlorine Gas. Dec 13, 2013
Add new Web site: EnvironmentalChemistry.com - Chlorine. Dec 13, 2013
Add new Web site: Chemguide - Manufacturing Chlorine using a Diaphragm and a Membrane Cell. Dec 13, 2013
Add new Web site: Tox Town - Chlorine. Dec 13, 2013
Add new Web site: Webelements - Chlorine. Dec 13, 2013
Add new Web site: Buzzle.com - Chlorine. Dec 13, 2013
Add new Web site: Centers for Disease Control and Prevention - Chlorine. Dec 13, 2013
Add new Web site: Royal Society of Chemistry - Chlorine. Dec 13, 2013
Add new Web site: Hyperphysics - Chlorine. Apr 12, 2013
Add new Web site: Chemical Elements.com - Chlorine (Cl). Apr 12, 2013
Add new Web site: Lenntech - Chlorine - Cl. Apr 10, 2013
Add new Web site: Rader's Chem4Kids.com - Chlorine. Apr 10, 2013
Add new Web site: Innvista - Chlorine. Nov 15, 2011
Article revised and updated. Apr 16, 2009
Added new Web site: Omniglot - NοΏ½shu. Feb 10, 2009
Article revised. Jan 29, 2009
Added new Web site: How Stuff Works - Healthguide - Chlorine Poisoning. Sep 25, 2008
Media added. Aug 28, 2008
Added new Web site: WebElements - Chlorine. May 26, 2008
Added new Web site: Los Alamos National Laboratory - Chlorine. May 07, 2008
Article revised and updated. Apr 24, 2008
Article revised and updated. Nov 07, 2007
Article added to new online database. Jul 20, 1998
View Changes:
Article History
Revised:
By: