The smell of freshly cut grass is actually a plant distress call.
31
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
4.5 pounds of sunlight strike the Earth each day.
27
Iron weighs more after it rusts.
68
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
Cold water weighs more than hot water.
93
One 75-watt bulb gives more light than three 25-watt bulbs.
57