Pumice is the only rock that floats on water.
14
Hot water can freeze faster than cold water.
181
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
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Neanderthal man had a brain capacity 100cc larger than modern man's.
50
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
The banana plant cannot reproduce itself. It can be propagated only by the hand of man.
155