Now that we know what a_V should be, we can move on to determine the asymmetry term (a_A) based on the shape of the binding energy curve across all of the oxygen isotopes, shown in the figure below.

Figure 1 shows the experimentally measured (cyan) and theoretically calculated (red) binding energy per nucleon (BE/A) for all observed isotopes of oxygen (from Table 2 on the previous page).

2(a) Vary the constant (a_A) in Table 1 until the shape of the theoretical binding energy curve matches the experimental data in Figure 1 as well as possible. We suggest you start by exploring what happens when you change the asymmetry parameter in steps of 5 MeV from 0 to 30 MeV. Note that you will not be able to get a perfect match.

2(b) Leave your answer for a_A in the Table to use it for the next activity. You will also want to make a note of your value.