CHM 116 Lecture 8: Nuclear Chemistry Continued 2
Document Summary
Mass defect: where does this energy come from, the masses of nuclei are always less than those of the individual parts, this mass difference is called the mass defect. The energy needed to separate a nucleus into its nucleons is called the nuclear binding energy. As we get heavier on the periodic table, the mass defect increases because more protons and neutrons are being packed into one place. There is an optimal binding energy for an atom. Binding energy is per nucleon (j), which is a neutron in this case. We stop at iron because it has the largest binding energy or is the most stable. This is why we stopped at iron in the first generations of stars. Lighter nuclei emit great amounts of energy by being combined in fusion. We are not efficient at fusion reactors yet, but we are more efficient at fission reactors (power plants)
