Chlorine (Cl)
"The Purifier, a hero who disinfects our water but has a toxic personality as a gas."
A memorable persona to anchor Cl in your mind.
3.214
Grams per cm³
-101.5
Celsius (°C)
175
Radius (pm)
Daily Life Link
The bleach used for cleaning and laundry.
Discovery & History
Year Discovered
1774
Discovered By
Carl Wilhelm Scheele
Origin of Name
"The name is derived from the Greek ''chloros'', meaning greenish yellow."
Technical Properties
Atomic Mass
35.45 u
Standard State
gas
Boiling Point
-34.04°C
Electron Configuration
[Ne] 3s23p5
1st Ionization Energy
12.968 eV
Electron Affinity
N/A
Oxidation States
"A dense, greenish-yellow gas with a sharp, bleach-like odor."
Did You Know?
It was the first element to be used as a chemical weapon in modern warfare, deployed as a poison gas during World War I.
The familiar smell of a swimming pool is not from chlorine itself, but from chemical compounds called chloramines, which form when chlorine reacts with sweat and urine.
Household bleach is a solution of sodium hypochlorite, a chlorine compound.
Table salt is a compound of sodium and chlorine (NaCl).