Balsa wood is classified as a hard wood!
41
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
The brain case [of Neanderthals] on the average was more than 13 percent larger than that of the average of modern man
61
A cubic yard of air weighs about 2 pounds at sea level.
31
Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
3
Pumice is the only rock that floats on water.
14
Indoor pollution is 10 times more toxic than outdoor pollution.
62