Nuclear+Chemistry

Nuclear chemistry entails interactions on the atomic nucleus, which behaves differently than the interactions involving electrons. The nucleus, first discovered in Rutherford's lab, received more attention during WWII during the research era of radioactivity. Radioactive atoms are unstable atoms that release components of its nucleus through nuclear splitting or set of decay reactions.

Nuclear Decay
There are three types of decay: alpha, beta and gamma. There are four beta cascades.

Alpha Decay The emission of two protons and two neutrons. They have low penetrative power and can be blocked by paper.

Beta Decay n/p > band of stability, i.e. there are too many neutrons. A neutron decomposes into a proton, electron and gamma rays. Therefore, the atomic number increases while a high energy electron is emitted with a gamma ray. They can be blocked by foil.

Gamma Decay High energy electromagnetic energy. They are partially blocked by lead. They are blocked fully by concrete. Concrete was used at Chernobyl to cover the reactors.

Splitting the Atom
Lise Meitner, the first female professor in Germany, is now credited as the major contributor to the splitting of Uranium 233. Her experiments involved bombarding U-233 with a neutron, a neural atom that could potential be absorbed and add mass. She expected to see an increase in mass, but her colleague, Otto Han who performed the experiments reported other lighter atoms. She reasoned that the release of energy was proportional to the mass loss through Einstein's equation E=mc^2. She correctly confirmed Einstein's equation and nuclear fission was born. However, since she was Jewish, she was not recognized for her work. Instead, Otto Hahn received the Nobel Prize in 1945 for the discovery of nuclear fission.

E-mc^2
Einstein's famous equation unifies fundamental concepts of all matter: Einstein helped us to understand that if we traveled at the speed of light, time would slow down. His equation was a unification of light and matter. The equation accounts for the large release of energy due to the loss of matter in atomic bombs, and the energy from the sun. Indeed, Einstein's equation is one the describes both death and life.
 * Energy: //electricity// and //magnetism// unified by Faraday; //electromagnetism// and //light// unified by Maxwell.
 * Mass: the conversation of mass discovered by Lavoisier.

The Atom Bomb
Although Einstein believed the energy of the atom would not be harnessed for a hundred year after his discovery of E=mc^2, the war sped up the creation of the atomic bomb. He was pressed by Leo Szilard to write to President Franklin Roosevelt warning him about the danger of the Nazi's potential to create and atomic bomb. Szilard indicated that the issue deflections of charged alpha particle bombardment on U-233 could be overcome by neutron bombardment. A single neutron bombardment could split a Uranium atom, releasing tremendous energy and two neutrons which would trigger other Uranium atoms causing a chain reaction. Einstein's letter to the President set forth the Manhattan Project of which Oppenheimer and Feynman were involved and led to the destruction of Nagasaki and Hiroshima.

Fast and slow reactions where investigated by Fermi and Wigner.

Electron Capture (K-Capture)
When the neutron-to-proton ratio is below the lower limit, protons absorb inner shell electrons and emit and electron, antineutrino and photon (x-ray or gamma) due to electron transition. The conversion of a neutron to a proton is illustrated in the Feynman diagram where are an down quark becomes and up quark by mediating a W- boson which releases an electron and antineutrino.