17
Cl
35.45
Chlorine (Cl)
Element 17 · Period 3 · Group 17
halogen
gas at room temp
p-block
About Chlorine
Reactive halogen gas. Used in water purification, PVC, and bleaches.
Physical Properties
Atomic Mass
35.45 u
State at 25°C
Gas
Melting Point
-101.5 °C
Boiling Point
-34.05 °C
Density
0.003214 g/cm³
Magnetism
Diamagnetic
Atomic Properties
Electron Configuration
[Ne] 3s² 3p⁵
Electron Shells
2, 8, 7
Electronegativity
3.16
Atomic Radius
79 pm
Ionization Energy
1251 kJ/mol
Oxidation States
-1 to +7
Discovery & History
Discovered By
Carl Wilhelm Scheele
Discovery Year
1774
Named By
Humphry Davy
Name origin: Greek: chloros (yellow-green)
Frequently Asked Questions
- Is Chlorine a metal, nonmetal, or metalloid?
- Chlorine is classified as a halogen.
- What state is Chlorine in at room temperature?
- Chlorine is a gas at standard room temperature (25°C).
- What is the atomic mass of Chlorine?
- Chlorine has an atomic mass of 35.45 atomic mass units (u).
- Who discovered Chlorine?
- Chlorine was discovered by Carl Wilhelm Scheele in 1774.
- Where is Chlorine on the periodic table?
- Chlorine is element number 17, located in period 3 and group 17.