Chlorine. Chlorine is the chemical most often used in swimming pools to control bacteria.
More Science Trivia
Magnetite. Magnetite is also called "lodestone".
Event Horizon. Light that originates from the one side of the event horizon will never reach an observer on the opposite side of the event horizon.
The Kangaroo And The Emu. The kangaroo is the national animal of Australia.
Malaria. Malaria is a an infectious disease transmitted by the bite of the Anopheles mosquito.
10. The U.S. Metric Board was abandoned in 1982.
Dog. The "dog days of summer" are named after Sirius, which is the "Dog Star".