The team at periodicvideos has created a TED-Ed Lesson for every element of the periodic table. This one is about bromine. It's one of the few elements that is liquid at room temperature and known for its odorous stench.
Bromine is used in plastics to make them less flammable. When a brominated material burns, the flame retardant produces hydrobromic acid. This hydrobromic acid interferes with the oxidation reaction of the plastic.