Indoor pollution is 10 times more toxic than outdoor pollution.
62
The bark of an older redwood tree is fireproof.
65
A ball of glass will bounce higher than a ball made of rubber.
73
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Rafflesia Arnoldii is the largest flower in the world and can grow as big as an umbrella.
42
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
A single speck of dust is half way in size between a subatomic particle and the Earth.
15