Pumice is the only rock that floats on water.
14
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
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
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
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
The sun is 330,330 times larger than the earth.
75
Aluminum used to be more valuable than gold!
84