Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
If the chemical sodium is dropped into water it will immediately and violently explode.
67
Columbia University has developed an artificial tree that passively soaks up carbon dioxide from the air using "leaves" that are 1,000 times more efficient than true leaves that use photosynthesis.
15
Pumice is the only rock that floats on water.
14
One barrel of petroleum holds 42 gallons.
20
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5