Pumice is the only rock that floats on water.
14
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
Pure water (H2O) does not conduct electricity on its own.
46
For every gallon of sea water, you get more than a quarter pound of salt.
45
A cesium atom in an atomic clock beats over nine billion times a second.
43
Iron weighs more after it rusts.
16
Sound travels fifteen times faster through steel than through air.
134