ATOMIC & NUCLEAR PHYSICS A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site deuterium A heavy isotope of hydrogen in which the nucleus contains one proton and one neutron (compared with ordinary hydrogen’s single proton). Deuterium was discovered and named (from the Greek deuteros meaning "second") by Harold Urey in 1933. In chemical equations it is denoted by the letter "D". The weight of the deuterium molecule, D2, is twice that of the hydrogen molecule, H2. Just as hydrogen forms the oxide H2O (ordinary water), so deuterium forms the oxide D2O (heavy water). A nucleus of deuterium is called a deuteron. On Earth, one atom of deuterium is found in about 6000 ordinary hydrogen atoms. Deuterium is used as a moderator to slow down neutrons. The abundance of deuterium in interstellar space is about 1.4 × 10-5 that of ordinary hydrogen. Because deuterium is difficult to manufacture and is quickly destroyed in stellar nuclear reactions, one view is that most of the deuterium found in the universe today was formed in the Big Bang. It is an important fuel for nuclear fusion. Related category    • ATOMIC AND NUCLEAR PHYSICS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP