Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Sound travels about 4 times faster in water than in air.
408
The bark of an older redwood tree is fireproof.
65
Diamonds can be shattered with a hammer.
-104
Hot water can freeze faster than cold water.
181
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
Iron weighs more after it rusts.
16