At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Balsa wood is classified as a hard wood!
41
A ball of glass will bounce higher than a ball made of rubber.
73
Iron weighs more after it rusts.
68
Indoor pollution is 10 times more toxic than outdoor pollution.
62
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Because heat expands the metal, the Eiffel Tower always leans away from the sun.
79
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118