107
Stories About Chemistry

INDEX

5.  How Many Hydrogens
Are There on Earth?

   The Nobel Prize is the highest award to a scientist. There are and have been very many scientists in the world, but just over a hundred of them have been awarded the Nobel Prize and they received it for the most outstanding of out­standing discoveries. Three of the Nobel Prizemen for 1932 were Murphy, Urey and Brickwedde.

   It was thought previously that there was only one hydrogen on Earth, that with an atomic weight of one. Murphy and his colleagues discovered a second hydrogen, twice as heavy. This was the hydrogen isotope having the atomic weight two. Isotopes are varieties of atoms with the same charge but different atomic weights. In other words, the nuclei of isotopic atoms contain an equal number of protons but different numbers of neutrons. Isotopes are known for all the chemical elements: some of them exist in nature; others have been obtained artificially by means of nuclear reactions.