Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Pumice is the only rock that floats on water.
14
Scientists aren't sure what color dinosaurs were.
312
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Each day, up to 150 species of life become extinct.
-23
If the chemical sodium is dropped into water it will immediately and violently explode.
67