A cubic yard of air weighs about 2 pounds at sea level.
31
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
One barrel of petroleum holds 42 gallons.
20
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
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
If the chemical sodium is dropped into water it will immediately and violently explode.
67
The brain case [of Neanderthals] on the average was more than 13 percent larger than that of the average of modern man
61