chlorine is highly reactive. it is more reactive than bromine but less reactive than fluorine. it reacts with most things to make chlorides. it can even burn things instead of oxygen. it dissolves in water to make a mixture of hypochlorous acid and hydrochloric acid. the more acidic it is, the more chlorine is made; the more basic it is, the more hypochlorous acid (normally turned into hypochlorite) and hydrochloric acid (normally turned into chlorides) are there. chlorine reacts with bromides and iodides to make bromine and iodine.