Describe the role of frederic joliot and Irene curie in the discovery of induced radioactivity?

Answer 1

Irene Joliet-Curie and Frederic Joliot

Irene Joliet-Curie and her husband Frédéric both were French scientists who shared winning the Nobel Prize award in chemistry in 1935 for artificially synthesizing a radioactive isotope of phosphorus by bombarding aluminum with alpha particles. 30P (15 protons/elections) was the first radioactive nuclide obtained through this method of artificially inducing radioactivity.

ImagesIrene Joliot-Curie and husband, Frederic Joliot:

Aluminum:

Polonium:

Artificially Induced Radioactivity TodayBefore this discovery of artificial induction of radioactivity, it was a common belief that atoms of matter are unchangeble and indivisible. After the very first discoveries made by Ernest Rutherford, Irene Joliot-Curie and her husband, Frederic Joliot, a new point of view was developed. The point of view that although atoms appear to be stable, they can be transformed into new atoms with different chemical properties. Today over one thousand artificially created radioactive nuclides exist, which considerably outnumber the nonradioactive ones created. Activation by neutron capture

Activation (or radioactivation) involves making a radioactive isotope by neutron capture, e.g. the addition of a neutron to a nuclide resulting in an increase in isotope number by 1 while retaining the same atomic number. Activation is often an inadvertant process occuring inside or near a nuclear reactor, where there are many neutrons flying around. For example, Cobalt-59 has a large neutron capture cross-section, making it likely that Co-59 in or near a nuclear reactor will capture a neutron forming the radioactive isotope Co-60. To avoid this inadvertant activation, the use of cobalt in or near reactors is minimized to the extent it is practical. Light water coolant in nuclear reactors inevitably contain traces of impurities which inadvertantly become neutron-activated making the primary water coolant radioactive. In boiling water reactors (BWR), the radioactive water/steam contaminates the inside of the steam turbine with radioactivity. Maintenance in a BWR steam turbine requires radiological controls to avoid contamination of the maintenance personnel.