Pumice is the only rock that floats on water.
14
One barrel of petroleum holds 42 gallons.
20
The use of emoticons affects our corresponding brain areas and can actually trigger emotions.
21
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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
During photosynthesis, plants emit light humans can’t see, but NASA can see that light from space - and they've even made maps of it!
21
