哈罗德·克莱顿·尤里

Harold Clayton Urey ( YOOR-ee; April 29, 1893 – January 5, 1981) was an American physical chemist who conducted pioneering work on isotopes. He earned the 1934 Nobel Prize in Chemistry "for his discovery of heavy hydrogen." He played a significant role in the development of the atom bomb, as well as contributing to theories on the development of organic life from non-living matter.

Born in Walkerton, Indiana, Urey studied thermodynamics under Gilbert N. Lewis at the University of California, Berkeley. After he received his PhD in 1923, he was awarded a fellowship by the American-Scandinavian Foundation to study at the Niels Bohr Institute in Copenhagen. He was a research associate at Johns Hopkins University from 1924 to 1929, before becoming an associate professor of chemistry at Columbia University. In 1931, he began work with the separation of isotopes that resulted in the discovery of deuterium.

During World War II, Urey turned his knowledge of isotope separation to the problem of uranium enrichment. He headed the group located at Columbia University that developed isotope separation using gaseous diffusion. The method was successfully developed, becoming the sole method used in the early post-war period. After the war, Urey became professor of chemistry at the Institute for Nuclear Studies, and later Ryerson professor of chemistry at the University of Chicago.

Urey speculated the early terrestrial atmosphere was composed of ammonia, methane, and hydrogen. One of his Chicago graduate students was Stanley L. Miller, who showed in the Miller–Urey experiment that if such a mixture were exposed to electric sparks and water, it can interact to produce amino acids, which are among the molecular building blocks of life.……

Early life

Harold Clayton Urey was born on April 29, 1893, in Walkerton, Indiana, the son of Samuel Clayton Urey, a school teacher and a minister in the Church of the Brethren, and his wife, Cora Rebecca née Reinoehl. Of mostly German ancestry, the family name had English origins. He had a younger brother, Clarence, and a younger sister, Martha.……

Deuterium

In the 1920s, William Giauque and Herrick L. Johnston discovered the stable isotopes of oxygen. Isotopes were not well understood at the time; James Chadwick would not discover the neutron until 1932. Two systems were used for classifying them based on their chemical and physical properties. The latter was determined using the mass spectrograph.……

Manhattan Project

By the time World War II broke out in Europe in 1939, Urey was recognized as a world expert on isotope separation. Thus far, separation had involved only the light elements. In 1939 and 1940, Urey published two papers on the separation of heavier isotopes in which he proposed centrifugal separation.……

Post-war years

After the war, Urey became professor of chemistry at the Institute for Nuclear Studies at the University of Chicago , and then became Ryerson professor of chemistry there in 1952. He did not continue his pre-war research with isotopes.……

Cosmochemistry and the Miller–Urey experiment

In later life, Urey helped develop the field of cosmochemistry and is credited with coining the term. His work on oxygen-18 led him to develop theories about the abundance of the chemical elements on Earth, and of their abundance and evolution in the stars. Urey summarized his work in The Planets: Their Origin and Development (1952).……

Death and legacy

Urey enjoyed gardening and raising cattleya, cymbidium and other orchids. He died at La Jolla, California on 5 January 1981, and is buried at the Fairfield Cemetery in DeKalb County, Indiana.

Apart from his Nobel Prize, he also won the Franklin Medal in 1943, the J.……