If the chemical sodium is dropped into water it will immediately and violently explode.
67
The banana plant cannot reproduce itself. It can be propagated only by the hand of man.
155
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
A cubic yard of air weighs about 2 pounds at sea level.
31
The most expensive material on the planet is antimatter - worth $62.5 trillion per gram.
18
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The bark of an older redwood tree is fireproof.
65
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55