18. In what sense can the mass loss observed upon forming a nucleus from subnuclear particles be considered a binding energy for the nucleus? Where has the missing mass gone?

19. How does the mass loss per nucleon change as atomic number changes? Which element has the greatest mass loss per nucleon? Does this make it especially stable, or unstable?

20. For elements with lower atomic number than that of the element in Question 19, is fission, or fusion, the energy-emitting process? Account for this in terms of binding energy and mass loss. Which is the energy-releasing process at higher atomic numbers?

21. What important quantities must be accounted for in balancing the equation for a nuclear reaction? How are these quantities represented in the symbols for atomic nuclei?

22. What is meant by a "stability zone" in a p-n plot?

23. How do nuclei with too many protons normally decay? What happens to the nuclear charge and mass number in the process? What does this decay process look like when represented on a p-n plot?