Chlorine is the second element of the Halogens group with chemical symbol Cl and atomic number 17 (Halogens family consists of F, Cl, Br, I, At; At is not in sale cause is highly radioactive and very dangerous for health, the other are not radioactive). Chlorine is a green/yellow gas at normal pressure and temperature.
Chlorine gas element 17 sample in mixture with Helium 70% (Cl 30% He 70%), this mixture prevents damages to the glass ampoule. Pure Chlorine sample.
This is the only way to get Cl2 sample in safe way and on own collection!