Margaret Melhase Fuchs (August 13, 1919August 8, 2006) was an American chemist and a co-discoverer, with Glenn T. Seaborg, of the isotope

caesium-137 Caesium-137 (), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nucle ...

Education and research career

In 1940, Melhase was an undergraduate in the college of chemistry at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

. She was president of the Student Affiliates of the American Chemical Society and was considering doctoral studies and a career in chemistry. Honors students typically took on research projects at the time, and she sought advice from her close friend, nuclear chemist Gerhart Friedlander; Friedlander was then a graduate student under the supervision of Glenn T. Seaborg, and he suggested she approach him for a project. She spoke to Seaborg in his lab, and he proposed they work together to search for a

Group 1 element The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names ...

among the fission products of

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

. Her laboratory was above those of Nobel Prize winners

Willard Libby Willard Frank Libby (December 17, 1908 – September 8, 1980) was an American physical chemist noted for his role in the 1949 development of radiocarbon dating, a process which revolutionized archaeology and palaeontology. For his contributio ...

and

Melvin Calvin Melvin Ellis Calvin (April 8, 1911 – January 8, 1997) was an American biochemist known for discovering the Calvin cycle along with Andrew Benson and James Bassham, for which he was awarded the 1961 Nobel Prize in Chemistry. He spent most of ...

. In March 1941, Melhase worked with Art Wahl. He handed her 100 grams of a uranium compound (

uranyl nitrate Uranyl nitrate is a water-soluble yellow uranium salt with the formula . The hexa-, tri-, and dihydrates are known. The compound is mainly of interest because it is an intermediate in the preparation of nuclear fuels. In the nuclear industry, it ...

) that had been neutron-irradiated by a

cyclotron A cyclotron is a type of particle accelerator invented by Ernest Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: Januar ...

. Using a Lauritzen quartz fiber electroscope, she discovered the Cs-137 several months later. Despite establishing herself as a promising young experimental scientist, nuclear research during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

was treated with strict secrecy and it was not publicized. Significant research on the isotope followed, but their results were not made available until after the war. Melhase received a bachelor's degree in

nuclear chemistry Nuclear chemistry is the sub-field of chemistry dealing with radioactivity, nuclear processes, and transformations in the nuclei of atoms, such as nuclear transmutation and nuclear properties. It is the chemistry of radioactive elements such as t ...

and planned to apply for graduate studies at UC Berkeley. However, the head of the chemistry department,

Gilbert N. Lewis Gilbert Newton Lewis (October 23 or October 25, 1875 – March 23, 1946) was an American physical chemist and a dean of the college of chemistry at University of California, Berkeley. Lewis was best known for his discovery of the covalent bon ...

, was refusing entry to women; the last woman the department admitted had gotten married shortly after her graduation and he considered her education a "waste". She worked for the Philadelphia Quartz Company in

El Cerrito, California El Cerrito (Spanish language, Spanish for "The Little Hill") is a city in Contra Costa County, California, United States, and forms part of the San Francisco Bay Area. It has a population of 25,962 according to the 2020 United States census, 2 ...

. She rejoined the

Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...

from 1944 to 1946. Without an advanced degree, she did not continue her career in science. Though references to her work are scant, Seaborg shares credit of his discovery of Cs-137 with her. Writing in 1961, he stated: He also wrote in 1990 that "it is appropriate to credit both G. T. Seaborg and M. Melhase for the 'birth' of cesium 137."

Personal life

Margaret was an only child, born in Berkeley, California to mother Margaret Orchard and father John Melhase, who worked as a geologist. During her time at UC Berkeley, Melhase was a member of the Berkeley Folk Dancers and edited the group's newsletter. She met mathematics professor Robert A. Fuchs at a folk dance, and the two married in 1945 and had three children. She and her husband moved to

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

. She was a supporter of social causes, organizing marches for agricultural workers and housing and aiding immigrant Laotian families in Los Angeles.

References

{{DEFAULTSORT:Melhase, Margaret 1919 births 2006 deaths 20th-century American chemists 20th-century American women scientists Manhattan Project people Nuclear chemists Scientists from Berkeley, California University of California, Berkeley alumni American women chemists 21st-century American women Women on the Manhattan Project