If the chemical sodium is dropped into water it will immediately and violently explode.
67
Brass doorknobs automatically disinfect themselves in about 8 hours.
18
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Sound travels about 4 times faster in water than in air.
408