Present and discuss the historical development of nuclear fission, starting with Fermi in 1934 and working up to production of nuclear bombs. Define fission in terms of nuclear division into 2 fragments with a resulting release of energy. Show and discuss images to highlight how the nucleus elongates and then divides. Uranium will divide into barium and krypton, with a release of energy equal to 7 times that of TNT/ atom. Present and discuss the formula for fission of uranium-235.
Review and analyze the homework questions from Wed.
Lab which demonstrate the principle of half life determination. Pennies are used as atomic nuclei, and the heads counted in a series of trials, which also presents the number of pennies remaining after each trial of removing only heads is performed. The mathematical probability is determined, and a graph drawn with the exponential rate of nuclei decay.
Define and discuss half life of radioactive isotopes. Compare the half life of radium, uranium and carbon to indicate the vast differences in theirs half life. Determine that after 20 half life's the amount of radioactivity becomes absent. Point out that radioactive decay is not affected by external conditions. Discuss how the half life is used to determine the age of an organic substance. Introduce the formula used to arrive at the age of an organic material. Work the formula amount remaining = original amount (No) x (1/2) ^t to arrive at the age of a substance. Discuss radioisotope use in diagnosis and treatment of some endocrine disorders.
Define and discuss decay half life of isotopes. Indicate the half life of radium, uranium, and carbon. Determine that the half life of isotopes is not affected by temperature, pressure, electric fields or magnetic fields. Discuss how half life is used to determine the age of carbon containing hydrocarbons. Discuss uses for radioactive isotopes in diagnosis and treatment of disease. Discuss the use of iodine radioisotopes for treatment of thyroid disorders.
Define transmutation of elements. Define and discuss beta decay and the beta particle and its charge. Introduce gamma rays and their effect on the body. Define ions and isotopes and use examples. Work examples to demonstrate the radioactive decay of uranium
Review alpha decay. Introduce beta decay and neutron decomposition to form a proton and electron.
Discuss gamma rays, ions, and the changes in charge. Write the transmutation formula for uranium to thorium by Alpha decay. Show examples of beta decay of thorium by emission of an electron from the decomposition of a neutron. Write and discuss a complete radioactive decay series for thorium to lead
lab designed to demonstrate the half life of an element. Penny coins are used, and the removal of all heads up coins after each trial are recorded along with the remaining numbers. The results tabulated and a graph drawn which demonstrates the exponential change.
A second lab is performed which demonstrates a fission reaction using dominoes.
lab to demonstrate how to determine the size of a nucleus utilizing collisions with marbles. The number of trials and hits are recorded and the probability determined. The size of the field, the number of nuclei determined by the number of marbles and the probability are used in a formula to determine diameter. The formula can be used to determine the radius of the nucleus of an atom.
Discuss and define radioactivity. Introduce the early work of Becquerel and Rutherford and their discovery of radioactive decay ores. Stress that the result of the decay is to produce a nuclei which is more stable than the original. Introduce alpha, beta, and gamma rays. Discuss alpha particles as helium nuclei with a mass of 4 and an atomic number of 2. Show transmutation of uranium by alpha particle decay. Work the alpha particle decay for plutonium and radium.
