Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65
Sound travels about 4 times faster in water than in air.
408
The brain case [of Neanderthals] on the average was more than 13 percent larger than that of the average of modern man
61
Pumice is the only rock that floats on water.
14
One ragweed plant can release as many as one billion grains of pollen!
51
0.3% of solar energy from the Sahara is enough to power the whole of Europe.
310
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
Approximately 70 percent of the earth is covered by water. Only 1 percent of this water is drinkable.
65