Binding Energy per Nucleon Curve - UNSOLVED PRACTICE SET
Chapter: Nuclei | Topic: Binding Energy per Nucleon Curve
BINDING ENERGY PER NUCLEON CURVE - UNSOLVED PRACTICE SET
Topic: Binding Energy per Nucleon Curve
Multiple Choice Questions
Q1. The binding energy per nucleon is maximum for:
- Hydrogen
- Helium-4
- Iron-56
- Uranium-235
Q2. The peak of the binding energy per nucleon curve occurs at approximately:
- 4 MeV
- 8.5 MeV
- 15 MeV
- 20 MeV
Q3. Energy is released in nuclear fission because:
- Heavy nuclei have more binding energy per nucleon than lighter fragments
- The fragments have greater binding energy per nucleon than the original heavy nucleus
- The total number of nucleons decreases
- Mass is created from energy
Q4. Energy is released in nuclear fusion because:
- Light nuclei have more binding energy per nucleon than heavier nuclei
- The product nucleus has greater binding energy per nucleon than the reacting nuclei
- The total number of nucleons increases
- Energy is conserved but not mass
Q5. The binding energy per nucleon curve shows that:
- All nuclei are equally stable
- Light nuclei are more stable than heavy nuclei
- Nuclei around iron-56 are the most stable
- Very heavy nuclei are the most stable
Q6. For nuclei heavier than iron-56:
- Fusion releases energy
- Fission releases energy
- Both fusion and fission release energy
- Neither fusion nor fission releases energy
Short Answer Questions
Q7. Draw a rough sketch of the binding energy per nucleon curve and label the important features.
Q8. Why is iron-56 considered the most stable nucleus? What is its approximate binding energy per nucleon?
Q9. Explain why energy is released when a heavy nucleus undergoes fission, using the binding energy per nucleon curve.
Q10. Explain why energy is released when two light nuclei undergo fusion, using the binding energy per nucleon curve.
Q11. Why cannot iron-56 be used as fuel for either fission or fusion reactions?
Q12. What is the significance of the binding energy per nucleon curve in understanding stellar evolution?
Long Answer Questions
Q13. Draw the binding energy per nucleon curve and explain its features. Discuss how this curve explains the release of energy in both nuclear fission and nuclear fusion.
Q14. Explain why the binding energy per nucleon increases rapidly for light nuclei, reaches a maximum around A = 56, and then gradually decreases for heavier nuclei. What does this tell us about nuclear forces?
Q15. Discuss the astrophysical significance of the binding energy per nucleon curve. How does it explain nucleosynthesis in stars and the abundance of elements in the universe?
Numerical & Application-based Problems
Q16. The binding energy per nucleon for uranium-235 is approximately 7.6 MeV, while for the fission fragments (average mass number 117) it is about 8.5 MeV.
(a) Calculate the total binding energy of uranium-235.
(b) Calculate the total binding energy of the fission fragments (assume two fragments of equal mass number).
(c) Calculate the energy released per fission event.
(d) Calculate the energy released when 1 kg of uranium-235 undergoes complete fission.
Q17. The binding energy per nucleon for deuterium (²H) is 1.1 MeV and for helium-4 is 7.1 MeV.
(a) Calculate the energy released when two deuterium nuclei fuse to form one helium-4 nucleus.
(b) Calculate the energy released per nucleon in this fusion reaction.
(c) Compare this with the energy released per nucleon in the fission of uranium-235 (about 0.9 MeV per nucleon).
Q18. In your school's science exhibition, a student creates a large display of the binding energy per nucleon curve.
(a) She marks the following nuclei on her curve: ²H (1.1 MeV/nucleon), ⁴He (7.1 MeV/nucleon), ¹²C (7.7 MeV/nucleon), ⁵⁶Fe (8.8 MeV/nucleon), ²³⁵U (7.6 MeV/nucleon). Plot these points on a rough binding energy per nucleon curve.
(b) Using the curve, explain why hydrogen bombs (fusion of light nuclei) and atomic bombs (fission of heavy nuclei) both release enormous amounts of energy, even though they work on opposite ends of the curve.
(c) The student explains that the Sun produces energy through fusion of hydrogen into helium. Calculate the energy released when 4 protons fuse into one helium-4 nucleus. (Binding energy per nucleon for hydrogen is effectively zero, and for helium-4 is 7.1 MeV.)
(d) A classmate asks why we can't build a nuclear reactor that fuses elements up to iron and then fissions elements heavier than iron to get unlimited energy. Explain the flaw in this reasoning using the binding energy per nucleon curve.
(e) In India's energy strategy, both nuclear fission (at reactors like Kudankulam) and research into nuclear fusion (through participation in ITER) are important. Discuss the advantages and challenges of each approach, using concepts from the binding energy per nucleon curve.