Chlorine

Chlorine (chemical symbol - Cl, from other-Greek.λλωρός - "yellow-green"[3], from Lat. Chlorum) is a chemical element of the 17th group (according to the outdated classification - the seventh group of the secondary subgroup, VIIB) of the second period of the periodic system of chemical elements of D. I. Mendeleev, with atomic number 17.

The simple substance chlorine (under normal conditions) is a poisonous suffocating diatomic gas (formula - Cl₂) of a yellowish-green color, heavier than air, with a pungent odor and a sweet, "metallic" taste.