Constant of proportionality equation

Suslik 1The Discovery of the NeutronAbstractDuring the first half of the 20th century, there were many important discoveries regarded the structure of atoms. One such discovery was James Chadwick’s discovery of the neutron in 1932. His discoveryof its existence as well as its naturehelped to provide a clearer picture of the atom and helped build the framework for themodernuse of nuclear technology.BackgroundJames ChadwickJames Chadwick was born in Bollington, England, in 1891. He accidentally signed up for physics at Victoria University of Manchester where he met Rutherford. During WWI he was interned in Germany, but he still continued his education. After the war, Chadwick went back to England where he became Rutherford’s assistant at theCavendish Laboratory in Cambridge, where he did much of his work including his discovery of the neutron. In 1935 he won the Nobel Prize in Physics for his discovery of the neutron.Prior Nuclear TheoryMany advancements were made in the field of nuclearphysics during the early 20th century. After Rutherford’s gold foil experiment, Rutherford
Suslik 2developed the nuclear atomic theory, in which a dense nucleus contains the positive charge of an atom and is surrounded by orbiting negatively charged electrons. When Rutherford discovered that hydrogen nuclei (protons) could be creating by disintegrating larger nuclei, he combined this observation with the known emission of electrons by nuclei (beta rays) in order to confirm his theory that the nucleus was composed of protons and electrons. In order to account for the difference between the atomic number (the positive charge of the nucleus) of an element and its atomic mass, the model placed extra electrons and protons inside of the nucleus. For instance, prior to Chadwick’s discovery, nitrogen-14’snucleus was believed to have 14 protons and 7 electrons and the alpha particle (a helium nucleus) was believed to have 4 protons and 2 electrons. The number of the extra proton-electron pairs in the nucleus was equal to the difference between the atomic number and the atomic mass, thus giving atoms their observed mass. Rutherford even suggested in a lecture that there might be a type of nucleus containing one proton and one electron which would be very hard to detect, which he dubbeda “neutron.”Discovering the neutronPrior ExperimentsOne experiment that helped to lead to Chadwick’s discovery was done by W. Bothe and H. Becker in which they found that beryllium, when exposed to alpha particles from polonium, emitted a penetrating radiation