The discussion centers on determining the Q value for lead in the context of the Rutherford scattering experiment, where gold's Q value is established at 79e due to its atomic number of 79. Participants suggest referring to a periodic table to find lead's atomic number, which is 82, indicating that lead has 82 protons in its nucleus. Consequently, the Q value for lead would be 82e. This value is essential for calculating the turning distance in the experiment when using lead instead of gold. Understanding these Q values is crucial for accurate interpretations of scattering results.