Iron weighs more after it rusts.
68
A cubic yard of air weighs about 2 pounds at sea level.
31
One 75-watt bulb gives more light than three 25-watt bulbs.
57
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
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
Every day, plants convert sunlight into energy equivalent to six times the entire power consumption of human civilization.
9
Some toothpastes and deodorants contain the same chemicals found in antifreeze.
38