One 75-watt bulb gives more light than three 25-watt bulbs.
57
Iron weighs more after it rusts.
68
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5
Stephen Hawking once tried to find potential time travellers by throwing a party and only sending out invitations after the party.
17
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Some toothpastes and deodorants contain the same chemicals found in antifreeze.
38
Indoor pollution is 10 times more toxic than outdoor pollution.
62
Liquid TIDE laundry detergent glows under a blacklight.
96