A cubic yard of air weighs about 2 pounds at sea level.
31
Balsa wood is classified as a hard wood!
41
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
Nearly 50% of the world's scientists are assigned to military projects.
71
Kissing actually has the biological purpose of passing on biological information and chemical signals to assess mating possibilities and status.
9
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199