Atomic Number: 17
Atomic Weight: 35.4527
Melting Point: 171.65 K (-101.5°C or -150.7°F)
Boiling Point: 239.11 K (-34.04°C or -29.27°F)
Density: 0.003214 grams per cubic centimeter
Phase at Room Temperature: Gas
Element Classification: Non-metal
Period Number: 3
Group Number: 17
Group Name: Halogen
Both Chlorine isotopes, Cl-35 and Cl-37, are used to study the toxicity of environmental pollutant and are usually supplied in the form of NaCl.