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Nuclear fission was discovered in December 1938 by chemists Otto Hahn and Fritz Strassmann and physicists Lise Meitner and Otto Robert Frisch. Fission is a nuclear reaction or radioactive decay process in which the nucleus of an atom splits into two or more smaller, lighter nuclei and often other particles.
Otto Hahn (German: [ˈɔtoː ˈhaːn] ⓘ; 8 March 1879 – 28 July 1968) was a German chemist who was a pioneer in the field of radiochemistry.He is referred to as the father of nuclear chemistry and discoverer of nuclear fission, the science behind nuclear reactors and nuclear weapons.
1940 – July – The paper explaining that Dr. Yoshio Nishina and Kenjiro Kimura discovered symmetric fission on the previously described test appeared in Nature. [ 12 ] [ 8 ] [ 13 ] The LibreTexts libraries based upon work supported by the National Science Foundation says, "Multiple combinations of symmetric fission products are possible for ...
She observed that radioactive recoil, which had been discovered by Harriet Brooks in 1904, could be a new way of detecting radioactive substances. They soon discovered two more new isotopes, bismuth-211 and thallium-207. [30] [31] [32] Meitner was particularly interested in beta particles. By this time, they were known to be electrons. Alpha ...
However, the end of the Cold War failed to end the threat of nuclear weapon use, although global fears of nuclear war reduced substantially. In a major move of symbolic de-escalation, Boris Yeltsin, on January 26, 1992, announced that Russia planned to stop targeting United States cities with nuclear weapons.
Hydrogen was known to be the lightest element, and its nuclei presumably the lightest nuclei. Now, because of all these considerations, Rutherford decided that a hydrogen nucleus was possibly a fundamental building block of all nuclei, and also possibly a new fundamental particle as well, since nothing was known to be lighter than that nucleus.
However, such predictions, assuming total war with nuclear arsenals at Cold War highs, have not been without criticism. [4] Such a horrific catastrophe as global nuclear warfare would almost certainly cause permanent damage to most complex life on the planet, its ecosystems, and the global climate. [5]
One must remember that only the naturally occurring β emitters were known at the time the theory was proposed. Later when positron decay was discovered, the process was easily incorporated within Fermi's original framework. On the basis of his theory, the capture of an orbital electron by a nucleus was predicted and eventually observed.