Fission · Paper 1 — Free Physics SL Practice Questions

The graph shows binding energy per nucleon as a function of nucleon number $A$. Region Y corresponds to medium-mass nuclei ($A \approx 56$–$90$) and Region Z corresponds to heavy nuclei ($A \approx 200$–$240$). Which statement correctly explains why energy is released when a heavy nucleus in Region Z undergoes fission to produce two nuclei in Region Y?

The binding energy per nucleon of uranium-235 is approximately $7.6 \text{ MeV}$. When uranium-235 undergoes fission, it splits into two fragments with nucleon numbers of approximately 95 and 140, each having a binding energy per nucleon of approximately $8.5 \text{ MeV}$. Which statement correctly explains why energy is released in this process?

The graph shows binding energy per nucleon against nucleon number. Iron-56 has the highest binding energy per nucleon. A uranium-235 nucleus undergoes fission, producing two daughter nuclei with nucleon numbers in the range 90–145. Which statement correctly describes the energy change during this process?