Iron weighs more after it rusts.
16
One gallon of used motor oil can ruin approximately one million gallons of fresh water!
71
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
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
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
Pure water (H2O) does not conduct electricity on its own.
46
German chemists made a replica of a trophy the size of one molecule.
68