Iron weighs more after it rusts.
16
One 75-watt bulb gives more light than three 25-watt bulbs.
57
The bark of an older redwood tree is fireproof.
65
Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
3
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
Indoor pollution is 10 times more toxic than outdoor pollution.
62
Aluminum used to be more valuable than gold!
84