Chlorine was discovered by Carl William Scheele at 1774 in Sweden.
Origin of name: from the Greek word "chloros" meaning "pale green".
Atomic Number: 17
Atomic Weight: 35.453
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: Haloge