Who is discovered isotopes

And November saw fresh claims that former Palestinian leader Yasser Arafat was killed by a deadly dose of polonium — the same isotope that doomed former KGB agent Alexander Litvinenko. Soddy was a chemist at Glasgow when he did much of his work on the products of radioactive decay. By the early s, he and other scientists had learned that radioactive substances such as radium and thorium transmuted into other elements as they decayed. But some of these new substances proved impossible to separate, even though they clearly had different half-lives.

Soddy realised that they were variants of the same elements; chemically identical but with different nuclei. Almost 20 years passed before James Chadwick actually discovered the neutrons that differentiate the nuclei of isotopes.

Soddy was a social reformer fascinated by economics, and enthusiastic that science could be a force for good in society. At first, he was hopeful that radioactive isotopes might be tapped as a source of energy. But then the first world war came, with explosives and poisonous gas furnished by science, and Soddy grew pessimistic.

He feared that bloated nuclei, straining to unleash their primordial energy, would be used for destructive purposes. Richards should be listed along with Fajans, Soddy, and Aston for fundamental contributions to establishing isotopes as part of the modern language of science.

As much credit should be given to the experimental proof as to the suggestion or naming of the concept. This is a preview of subscription content, access via your institution. Rent this article via DeepDyve. Aston, F. Nature , a Brief announcement of isotopes of atomic weights Nature , b December Isotopes of chlorine and mercury. Nature , — c July 15 Historical background and report of isotopes of 18 elements.

Nature , d December 9. Report of the number of isotopes of 18 elements. A summary without references. Great Britain 23 , — b. Edward Arnold Publisher, London a. Google Scholar. Baly, E. Baxter, G. Science 68 , — Article Google Scholar. Conant, J. Science , — A Biographical Memoir, pp.

National Academy of Sciences Crookes, W. Nature 34 , — Ephraim, F. English edition by P. Thorne, Gurney and Jackson, pp. Ernst, R. Encyclopedia of Nuclear Magnetic Resonance, vol. Evans, R. McGraw-Hill, New York The mass number of an atom is determined by the number of nucleons both protons and neutrons in its nucleus, and each isotope of a given element has a different mass number. Carbon, carbon, and carbon, for example, are three carbon isotopes with mass numbers of 12, 13, and 14, respectively.

Carbon with an atomic number of 6, which means that every carbon atom has 6 protons, giving these isotopes neutron numbers of 6, 7, and 8, respectively. The radiochemist Frederick Soddy was the one who discovered the isotopes. In , based on observations of radioactive decay chains that revealed about 40 different species referred to as radioelements i.

Richards discovered differences in the atomic weight of lead from various mineral sources in , which he attributed to differences in isotopic composition caused by different radioactive origins. The discovery of isotopes was based on two separate lines of inquiry, the first of which was the observation of radioactivity. By , it was clear that certain radioactive processes, discovered a few years before by French physicist Henri Becquerel, could change one element into another.

Tiny quantities of certain radioactive substances never seen before were found in ores of the radioactive elements uranium and thorium, in particular. These compounds were considered to be elements and were given unique names as a result.

Ionium was produced by uranium ores, and mesothorium was produced by thorium ores. Murphy discovered the effect of isotopes on the mass of an atom. The term isotope is a combination of the Greek word Isos, which means equal, and topos, the word for place. Before the discovery of the isotope, it was assumed that the mass of a standard number of atoms in a chemical element was the most basic feature of the density of the element.

Isotopes presented to the world a component of the element that was smaller than an atom and derived from an atom.

These components were sometimes heavier in mass than the main chemical. The discovery of the isotope was not only useful to chemistry but for many other disciplines.

The best known use of the isotope is in nuclear weapons and energy. In medicine, isotopes are used in photosynthesis to study the effect of animal metabolism in food. They are also used in bone imaging and radiation therapy to treat cancer. Isotopes are used in the sensors of smoke detectors in buildings.

Archeologists use carbon isotopes to determine the age of an object, a process known as carbon 14 dating.