You eat this deadly gas every day


  • Atomic Symbol- Cl
  • Atomic Number- 17
  • Atomic Weight- 35.4
  • Group- 17
  • Period- 3
  • Color- Greenish yellow
  • Classification- Non-metallic

History of Chlorine

Chlorine was discovered in 1774 by Carl Wilhelm Scheele. It was originally found through the reaction of hydrochloric acid and manganese dioxide.

What is Chlorine used in?

  • Chlorine is found in many everyday products. They include drinking water (disinfects the water)
  • Paper products,
  • Cleaning supplies
  • Dyes
  • Antiseptics
  • Medicines
  • Paints
  • Plastics
  • Petroleum products.


Chlorine is a greenish yellow gas when at room temperature. It can combine with almost every element. If it is inhaled in large amounts, it can be deadly.

Biology / Geology

Chlorine is needed in humans. There is 1200000 ppb by weight, 210000 atoms relative to C = 1000000.

Properties of Chlorine

  • Density of solid: 2030 kg
  • Melting point: -101.5 degrees Celcius
  • Boiling point: -34.04 degrees Celcius

Interesting Facts

  • The solid state of chlorine is orthorhombic.

  • Chlorine atoms have 17 electrons.

  • Combines with sodium to create table salt.

  • Is in the group called halogens.

  • Found commonly as NaCl (solid or seawater).

  • Liquid chlorine can burn the skin.

  • The name “chloros” in Greek means pale green.