Iron weighs more after it rusts.
68
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
Sound travels fifteen times faster through steel than through air.
134
Balsa wood is classified as a hard wood!
41
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
A cubic yard of air weighs about 2 pounds at sea level.
31
Iron weighs more after it rusts.
16