Question

Which combination of properties correctly describes heavy nuclei?

Options

• Mass number less than 30; binding energy per nucleon less than \(8.0\ \mathrm{MeV}\); lower stability

• Mass number greater than 170; binding energy per nucleon less than \(8.0\ \mathrm{MeV}\); lower stability

• Mass number greater than 170; binding energy per nucleon greater than \(8.0\ \mathrm{MeV}\); higher stability

• Mass number 30 to 170; binding energy per nucleon \(\approx 8.0\ \mathrm{MeV}\); higher stability

Answer 1

Heavy nuclei have mass numbers greater than 170. Like light nuclei, they fall outside the flat stable region of the curve, so their binding energy per nucleon is less than \(8.0\ \mathrm{MeV}\), which corresponds to lower stability.