Brass doorknobs automatically disinfect themselves in about 8 hours.
18
Iron weighs more after it rusts.
68
Sound travels about 4 times faster in water than in air.
408
A 'jiffy' is an actual unit of time for 1/100th of a second!
66
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
A coal power station puts 100 times more radiation into the air than a nuclear power plant producing the same amount of energy.
7
Nylon is made from coal and petroleum.
42