Pumice is the only rock that floats on water.
14
Marie Curie, the Nobel prize winning scientist who discovered radium, died of radiation poisoning.
57
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Nylon is made from coal and petroleum.
42
In 1999, Harvard physicist Lene Hau was able to slow down light to 17 meters per second and in 2001, was able to stop light completely.
39
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
A coal power station puts 100 times more radiation into the air than a nuclear power plant producing the same amount of energy.
7