'''Chlorine''' is in Group 7 of the periodic table, making it a [[halogen]] along with such elements as [[fluorine]], [[bromine]] and [[iodine]]. It has an atomic number of 17. Like other halogens, it is reactive to most metals and is never found free in nature. The chlorine molecule (Cl<sub>2</sub>) contains two chlorine atoms bonded together. | '''Chlorine''' is in Group 7 of the periodic table, making it a [[halogen]] along with such elements as [[fluorine]], [[bromine]] and [[iodine]]. It has an atomic number of 17. Like other halogens, it is reactive to most metals and is never found free in nature. The chlorine molecule (Cl<sub>2</sub>) contains two chlorine atoms bonded together. |