## Problem-Solving Strategies For Reaction And Binding Energies and Activity Calculations in Nuclear Physics

*Identify exactly what needs to be determined in the problem (identify the unknowns)*. This will allow you to decide whether the energy of a decay or nuclear reaction is involved, for example, or whether the problem is primarily concerned with activity (rate of decay).*Make a list of what is given or can be inferred from the problem as stated (identify the knowns).**For reaction and binding-energy problems, we use atomic rather than nuclear masses.*Since the masses of neutral atoms are used, you must count the number of electrons involved. If these do not balance (such as in \({\beta }^{+}\) decay), then an energy adjustment of 0.511 MeV per electron must be made. Also note that atomic masses may not be given in a problem; they can be found in tables.*For problems involving activity, the relationship of activity to half-life, and the number of nuclei given in the equation \(R=\cfrac{\text{0.693}N}{{t}_{1/2}}\) can be very useful.*Owing to the fact that number of nuclei is involved, you will also need to be familiar with moles and Avogadro’s number.*Perform the desired calculation; keep careful track of plus and minus signs as well as powers of 10.**Check the answer to see if it is reasonable: Does it make sense?*Compare your results with worked examples and other information in the text. (Heeding the advice in Step 5 will also help you to be certain of your result.) You must understand the problem conceptually to be able to determine whether the numerical result is reasonable.

### PhET Explorations: Nuclear Fission

Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor!