• Atomic number 17
• Atomic symbol Cl
• Found in the Halogen Family (group 17)
• Atomic weight 35.453 g/mol
• Most often found as a gas
• There are seven electrons in its valence shell

Chlorine has been known about since 300 B.C. Around 1200 it was used to disolve gold and today aqua regia is one of the only mixtures that will disolve gold. Chlorine was first studied by a swedish scientist named Carl Wilhelm Scheele. He called it "dephlogisticated muriatic acid air". Even though he "discovered" it he didnt dub it an element. He thought it was an oxide. In 1809 Joseph Lussac and Jacques Thenard wanted to decompose muratic acid so they mixed it with charcoal to release the element from it. They failed. Later Sir Humphry Davy tried the same expiriment and had the same test and said it was an element not a compound. Chlorine gas was first used as a weapon in 1915 at Ypres by the Germans in WW1 and the results were quite horrifying because they didnt have gas masks.

How its Made

The main way that chlorine is made is they pass an electric charge through salt disolved in water. The common chemical term for that is Naocl. Then the hydrogen splits from the chlorine and the oxygen and nitrogen. Half of the stuff is salt and the other half is chlorine gas or Mustard gas. Salt is made by passing an electric charge through the water and it splits and if you sift out the salt almost half of the container will be salt. The workers need gas masks or protection from the small amounts of chlorine gas that is released from the production of salt. There are also alot of ways to make chlorine gas by mixing chlorox with ammoniam nitrate.