Nylon is made from coal and petroleum.
42
Iron weighs more after it rusts.
16
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
The average home creates more pollution than does the average car.
33
One gallon of used motor oil can ruin approximately one million gallons of fresh water!
71
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