American chemist

In 1934, Harold Urey was awarded the Nobel Prize in chemistry for his discovery of deuterium, an isotope, or species, of hydrogen in which the atoms weigh twice as much as those in ordinary hydrogen. Also known as heavy hydrogen, deuterium became profoundly important to future studies in many scientific fields, including chemistry, physics, and medicine. Urey continued his research on isotopes over the next three decades, and during World War II, his experience with deuterium proved invaluable in efforts to separate isotopes of uranium from each other in the development of the first atomic bombs. Later, Urey's research on isotopes also led to a method for determining the earth's atmospheric temperature at various periods in past history. Already a scientist of great honor and achievement, Urey's last great period of research brought together his interests and experiences to a study of the...