How was deuterium discovered by Harold Urey?
Harold C. Urey discovered deuterium in 1931 by applying theoretical principles to the separation of isotopes.12
Urey hypothesized that there would be a difference in the vapour pressures of ordinary molecular hydrogen () and hydrogen deuteride (), suggesting that these substances could be separated through the distillation of liquid hydrogen. After reading about indirect evidence for the existence of a heavy hydrogen isotope in a 1931 Physical Review article, Urey devised an experiment to test his theory.123
He obtained samples of hydrogen expected to be enriched in the heavier isotope and successfully detected deuterium by observing its atomic spectrum in the residue of the distilled liquid hydrogen. This discovery, which confirmed the existence of an isotope with twice the mass of ordinary hydrogen, earned Urey the Nobel Prize for Chemistry in 1934.123