Athena
TR
Event / publication / experimentBranches1939

Nuclear fission

Otto HahnFritz StrassmannLise MeitnerOtto Robert Frisch

This page delivers no verdict; it presents claims and evidence with their sources. No theory in science is absolute. Method

For everyone

At the end of 1938 Hahn and Strassmann found barium when they bombarded uranium with neutrons. Meitner and Frisch explained this as the uranium nucleus splitting in two and releasing a large amount of energy. The discovery became the basis of both nuclear power plants and the atomic bomb. Meitner's contribution was not recognised by the Nobel Prize.

For specialists

Using the liquid-drop model, Meitner and Frisch estimated that fission releases about 200 MeV, coming from the mass difference of the products (E = mc²). The release of 2–3 neutrons per fission on average makes a chain reaction possible. The first controlled chain reaction was achieved on 2 December 1942 in Chicago Pile-1.

Claims

Evidence

Supporting

Experiment

Barium isotopes were identified chemically among the products of irradiated uranium.[1]

Experiment

Frisch directly measured the large pulses produced by fission fragments in an ionisation chamber.[3]

Challenging

—

Connections

Parent

Energy

Related

Special relativityMaking gold by nuclear transmutation

Show in tree →

Sources

  1. ArticleHahn, O.; Strassmann, F. (1939). Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle. Naturwissenschaften 27, 11–15DOI 10.1007/BF01488241archive
  2. ArticleMeitner, L.; Frisch, O. R. (1939). Disintegration of uranium by neutrons: a new type of nuclear reaction. Nature 143, 239–240DOI 10.1038/143239a0archive
  3. ArticleFrisch, O. R. (1939). Physical evidence for the division of heavy nuclei under neutron bombardment. Nature 143, 276DOI 10.1038/143276a0archive

Search the literature

Look for scholarly work on this topic in other indexes:

Google Scholar ↗Semantic Scholar ↗BASE ↗CORE ↗arXiv ↗DergiPark ↗

Cite this page

APA

Athena contributors. (2026). Nuclear fission. Athena: The tree of human knowledge. Retrieved November 1, 2026, from https://latifkedi.github.io/athena/en/d/nukleer-fisyon/

BibTeX
@misc{athena_nukleer_fisyon,
  title        = {Nuclear fission},
  author       = {{Athena contributors}},
  year         = {2026},
  howpublished = {\url{https://latifkedi.github.io/athena/en/d/nukleer-fisyon/}},
  note         = {Athena: The tree of human knowledge. Accessed: 2026-11-01}
}

Added: September 27, 2026 · Last changed: September 27, 2026 · Page history

✎ Suggest a correction