← Periodic Table
17
p
Cl
35.4500

Chlorine

Halogen

Atomic Properties

Atomic Number
17
Atomic Mass
35.4500 u
Electron Configuration
[Ne] 3s2 3p5
Electronegativity
3.16
Block
p-block
Group
17
Period
3

🌡 Physical Properties

Phase (STP)
gas
Melting Point
171.60 K
Boiling Point
239.11 K
Density
0.0032 g/cm³

About Chlorine

Yellow-green toxic gas; used to disinfect water and make PVC.

🔬 Isotopes of Chlorine

Chlorine has 2 naturally occurring isotopes.

IsotopeMass NumberAtomic Mass (u)AbundanceType
35Cl3534.9688526875.76%Stable
37Cl3736.965902624.24%Stable

Data source: NIH PubChem (aggregated from IUPAC, NIST)