Diplogen; Heavy hydrogen

Hydrogen, Isotope

Deuterium (Symbol: ²H, earlier, D) (from the Greek: δεύτερος (deúteros) = “the second”) is a stable isotope of hydrogen with a relative atomic mass of 1.00782519 mu and a nuclear spin of 1. Mass spectrometry and various scattering experiments reveal two elemental particles in its atomic nucleus, a positively charged proton and an uncharged neutron. These observations gave rise to its name. Other natural isotopes of hydrogen are Protium (¹H) (one proton, 2.01410222 mu, nuclear spin ½) and Tritium (³H) (one proton two neutrons, 3.01610497 mu, nuclear spin ½, radioactive) (Greenwood and Earnshaw 1984). Because of its mass, deuterium is also called “heavy hydrogen.”

Deuterium was discovered in 1931 by Harold C. Urey, who received the Noble Prize in chemistry (1934) for this finding.

Hydrogen is the most abundant element in the universe (ca. 76%). The average deuterium-to-hydrogenratio in the universe...