CHAPTER 13 NUCLEAR CHEMISTRY Elementary Nuclear Particles and Reactions Nuclei contain two kinds of particle protons and neutrons particles nuclei of the He atom particles electrons that originate from the nuclei of atoms in nuclear decay processes rays quanta of electromagnetic radiation photons o A mass number o Z atomic number When a particle e and anti particle positron meet they annihilate and produce photons which carry energy corresponding to the mass of the particle E mc2 Neutrino and antineutrino line should be above o Interact so weakly with matter they can go through the entire earth without ever interacting with anything Nuclear Reactions Fusion Fusion steps in proton proton cycle combine smaller nuclei to form larger ones Fission producing smaller nuclei from larger ones Nuclear Stability Binding Energy Nuclear Forces forces that bind the nuclei into stable entities o Stronger than electromagnetic forces b c the protons in the nucleus strongly repel each other due to their positive charge Neutrons provide extra nuclear attraction offset electrostatic repulsions of the o protons o Bigger the nuclei bigger the ratio between protons and neutrons bigger than 1 Binding energy of nuclei per nucleon as a function of the mass number increases almost steadily from the smallest nucleus to the nucleus or iron 57 o Beyond that the binding energy decreases monotonically Natural tendency of nuclei is to come together to form larger nuclei which increases the binding energy per nucleon thereby producing a more stable nucleus up to iron 57 Nuclear Reactions Fission Fission reaction certain nuclei break apart to smaller fragments Radioactive Dating Calculate decay of carbon 14 in something