The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
Out of all the senses, smell is most closely linked to memory.
146
Indoor pollution is 10 times more toxic than outdoor pollution.
62
Most liquid laundry detergents are alive with living organisms that help to break down stains!
88
Balsa wood is classified as a hard wood!
41
If the chemical sodium is dropped into water it will immediately and violently explode.
67
Hot water can freeze faster than cold water.
181
