Deuterium is an isotope of hydrogen. The most common form of hydrogen has one proton and no neutrons, but deuterium contains a proton and neutron in its nucleus. This isotope has the same chemical properties as hydrogen and can combine with oxygen to create water. Deuterium water is also known as 'heavy water'. Heavy water is used in many applications such as nuclear magnetic resonance, neutron moderation in nuclear power plants and organic chemistry.
Urey discovered deuterium by investigations of heavy water in 1931 and was important in the understanding of the concepts of isotopes. Find out what else occurred on this day in science history.