Basic Information

Name: Chlorine 
Symbol: Cl 
Atomic Number: 17 
Atomic Mass: 35.4527 amu 
Melting Point: -100.98 °C (172.17 K, -149.764 °F) 
Boiling Point: -34.6 °C (238.55 K, -30.279997 °F) 
Number of Protons/Electrons: 17 
Number of Neutrons: 18 
Classification: Halogen 
Crystal Structure: Orthorhombic 
Density @ 293 K: 3.214 g/cm3 
Color: green
Date of Discovery: 1774 
Discoverer: Carl Wilhelm Scheele 
Name Origin: From the Greek word khlôros (green) 
Uses: Water purification, bleaches 
Obtained From: Salt