A single speck of dust is half way in size between a subatomic particle and the Earth.
15
In zero gravity, a candle's flame is round and blue.
16
Most dust particles in your house are made from dead skin!
67
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5
Pumice is the only rock that floats on water.
14