Birth Date: November 8, 1926
Place of Birth: Terril, Iowa, United States
Nationality: American
Occupation/Field of Study An American nuclear chemist who worked with transuranium elements and made important discoveries about nuclear fission.


KEYWORDS: Nuclear Chemistry, Chemistry, Science, Woman, Darleane C. Hoffman, Seaborgium, researcher, innovator.


Darleane C. Hoffman is one of the most appreciated scientists in nuclear chemistry. Her most visible discovery is connected with her mentor Glenn T. Seaborg. Darleane was a part of the group of researchers when the new element was discovered and they named it “seaborgium”. In 1971 she discovered primordial plutonium in nature and it is very significant because they found remnants of the element on the field after plutonium bomb which was dropped over Nagasaki in 1945.¹ (p. 103)

At the times Darleane was finishing her studies it was normal for women to choose either to have a career or a family, but she wanted to have both. Social pressure did not stop her from studying and analysing evasive elements, such as transuranium elements. She published her discovery of small amounts of a plutonium isotope in a several billion years old rock formation, even though it was believed that heavy elements do not exist in nature.⁵

Darleane Hoffman was an outstanding scientist who was also interested in gender issues. For instance, during her academic visit in Norway she noticed that Norwegian women were treated much more equally than those in the United States. She was surprised that women were more independent and she decided to continue this attitude in social and academic sphere.¹ (p. 105)

Nevertheless, Darleane Hoffman is the second woman awarded the Priestley Medal which is the higher honour of American Chemical Society.⁶ She received many other recognitions and awards during her research, worked for several government advisory boards and wrote more than 200 research papers on the chemistry topics related to heavy elements and nuclear chemistry.⁶



Darleane C. Hoffman was born in Terril, northwestern Iowa on the 8th of November 1926. Her father was a school principal and math teacher which had an impact on Darleane’s career orientation. Furthermore, she often worried that other students would think she was being favoured, and so, she did not even dare to ask for help with homework.³ (p. xxiii) After high school she enrolled in Faculty of Arts at the Iowa State College but soon changed her major to chemistry. She was excited to study chemistry and one of the reasons was her chemistry professor, Nellie Nylor. She was an inspiration to Darleane and a role model for many young women, who were taught that a woman has to choose between career and family.⁵ However, Darleane was an exceptional student with the highest grade averages. After graduating from high school she continued her studies and finished her PhD specialized in nuclear chemistry in 1951.¹ (p. 103) It was in high school when she met her future husband Marvin Hoffman and they married after she earned her doctorate. She had several positions in different national laboratories around the country. She was a senior advisor and charter director for the G. T. Seaborg Institute at the Lawrence Livermore National Laboratory.⁶ Afterward she held position at Oak Ridge National Laboratory in Tennessee for one year and then followed her husband to Los Alamos National Laboratory in New Mexico.¹ (p. 103) During their work Darleane and her husband expanded their family and two children were born. It should be noticed that Darleane never stopped working. “They had a woman who came every day to take care of children until her mother moved there to live nearby in 1964, and from then on she helped¹ (p. 103).”

Next step in Darleane’s career after working on spontaneous fission of elements in Los Alamos, was Berkeley. Between 1978 and 1979 she worked at the University of California at Berkeley with a Guggenheim fellowship in Glenn Seaborg’s group.¹ (p. 103)

They finally moved to Berkeley in 1984 and she became the leader of the Heavy Element and Radiochemistry Group.⁶

While studying and working later on, she faced many challenges regarding gender discrimination. When she started her career as professor, her husband told her that she should not be amazed if “she did not get too many graduate students because probably some of the young men would not want to work for a woman⁴ (p. 163).” Before this she experienced discriminative response from the radiochemistry laboratory where she was supposed to get a job: “/…/ I am sorry but we don’t hire women in that division! /…/”¹ (p.103). She was feeling offended and, after this happened, never trusted personnel departments again.

However, the plutonium-244 discovery was Darleane Hoffman’s greatest achievement. It was the most publicized scientific achievement even though not the only one.¹ (p. 105) Another significant discoveries were the symmetric mass division in spontaneous fission and heavy, short-lived fermium isotopes.¹ (p. 105)

An extremely important phenomenon Darleane was willing to address was unequal payment regarding women and men. While being a division leader at Los Alamos, she participated in management of payment and financial distribution. Regarding the concerns about women not receiving equal payment to men in equivalent positions, each division got a sum of money to make a pay gap smaller.¹ (p.105) “They [we] distributed the money according to merit among the women and Darleane [I] felt like that this was one of those win-win situations¹ (p. 106).” Nevertheless, this was not her only concern. The most important in her opinion was ”to investigate the climate and the concepts of tenure and why so many women choose not to even apply for positions at the major research universities in the U.S.¹ (p. 106).”



Darleane was a part of the greatest discoveries about heavy elements and one of the most visible was definitely primordial plutonium in nature. She worked with Lise Meitner and Otto Frisch on the remnants of plutonium in nature, after they interpreted the nuclear fission experiment of uranium.¹ (p. 104) Later on Seaborg and his associates artificially produced plutonium, “which then played a conspicuous role in the development of atomic bombs¹ (p. 103).”



“The beginning Home Economics Chemistry at Iowa State was taught by Prof. Nellie Naylor, and largely due to her outstanding teaching I found myself more interested in Chemistry than anything I had ever studied. She had a way of making it all seem so beautifully logical as well as relevant to a host of everyday problems. Consequently, I decided by the second quarter that I would switch my major to Chemistry. This somewhat unconventional choice caused my Applied Art Counselor to ask me, “Do you really think chemistry is suitable profession for a woman?”! I replied that I was quite sure it was.”

Preface of: Hoffman, C. Darleane / Albert Ghiorso / Glenn T. Seaborg (2000), The Transuranium People: The Inside Story, London, Imperial College Press.


“Once in Los Alamos, I immediately started calling the personnel department to ask about my job in the Radiochemistry Group of the Test Division and they told me, “There must be some misunderstanding, we don’t hire women in that Division.” Having never before run into such discrimination, I was totally taken aback and asked them to please try to circulate my application and find out where my job was supposed to be, but to no avail.”

Preface of: Hoffman, C. Darleane / Albert Ghiorso / Glenn T. Seaborg (2000), The Transuranium People: The Inside Story, London, Imperial College Press.


“I found Norwegian women were treated much more equally than women in the U.S. at that time. It was all right for women to go out to dinner alone but men also didn’t open doors for them, etc. However, if you asked for help it was willingly given. I learned a great deal and developed a much more independent attitude socially and scientifically after our year there.”

Hargittai, Magdolna, (2015), Women Scientists: Reflection, Challenges, and Breaking Boundaries, New York, Oxford University Press. (p. 105)



1978: Guggenheim Fellowship;

1983: the first woman to be awarded with ACS Award for Nuclear Chemistry;

1990: awarded Garvan-Olin Medal;

1997: awarded National Medal of Science;

2000: the second woman to be awarded with Priestley Medal, the highest honor of the American Chemical Society.


Hoffman, C. Darleane, (1980), Nuclear Properties of Mendelevium, Los Alamos National Laboratory.

Hoffman, C. Darleane / Albert Ghiorso / Glenn T. Seaborg (2000), The Transuranium People: The Inside Story, London, Imperial College Press.

Nitsche, Heino / Darleane C. Hoffman / Ralf Sudowe / Jon M. Schwantes / Charles M. Folden (III.) (2005), Neuron Capture Experiments on Unstable Nuclei, United States, National Nuclear Security Administration.




  1. Hargittai, Magdolna, (2015), Women Scientists: Reflection, Challenges, and Breaking Boundaries, New York, Oxford University Press.
  2. Hargittai, Istwán / Magdolna Hargittai (2006), Candid science VI: more conversations with famous scientists, London, Imperial College Press.
  3. Hoffman, C. Darleane / Albert Ghiorso / Glenn T. Seaborg (2000), The Transuranium People: The Inside Story, London, Imperial College Press.
  4. Hargittai, Balazs / Magdolna Hargittai / Istvan Hargittai (2014), Great Minds: Reflections of 111 Top Scientists, New York, Oxford University Press.
  5. Chemical Heritage Foundation, Darleane C.Hoffman (last updated November 3, 2015), <> (last accessed 15 Nov. 2017)
  6. Yarris, Lynn (2000), Chemists Award Darleane Hoffman Highest Honor in Their Field, Science Beat, <> (last accessed 24 Nov. 2017).
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