Pumice is the only rock that floats on water.
14
Indoor pollution is 10 times more toxic than outdoor pollution.
62
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
One ragweed plant can release as many as one billion grains of pollen!
51
Each day, up to 150 species of life become extinct.
-23
Pure water (H2O) does not conduct electricity on its own.
46