chlorine

noun

1. (uncountable, usually)A toxic, green, gaseous chemical element (symbol Cl) with an atomic number of 17.

   “When TCCA touches a small amount of water and doesn’t dissolve, “it can experience a chemical reaction, generating heat and causing the decomposition of the chemical, which in turn produces toxic chlorine gas and can produce explosive nitrogen trichloride,” a 2023 report by the CSB said.”

2. (countable, usually)A single atom of this element.
3. (countable, usually)A chlorine-based bleach or disinfectant.

   “The mechanism involved in the explosive reaction between swimming pool chlorine (calcium hypochlorite) and brake fluid (polyethylene glycol), a possible improvised explosive mixture, has been studied by means of the gaseous products produced.”

   “Chlorines are useful for disinfecting water and for housekeeping disinfectants.”

   “Of the chemical solutions, chlorine tablets will kill many pathogens, but not some parasites like giardia and amoebic cysts.”