Out of all the senses, smell is most closely linked to memory.
146
Iron weighs more after it rusts.
16
Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
15
Pure water (H2O) does not conduct electricity on its own.
46
Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
Oak trees produce 2,200 acorns in a season, but each acorn only has a 1 in 10,000 chance of becoming an oak tree.
304
If you are locked in a completely sealed room, you will die of carbon dioxide poisoning first before you will die of oxygen deprivation.
117
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51