Key relationship
B≈avA−asA^(2/3)−acZ(Z−1)/A^(1/3)−aa(A−2Z)²/A+pairing.
Physics · Class 12
Binding energy per nucleon
Intermediate nuclei have high binding per nucleon. Light nuclei can release energy by fusion and heavy nuclei by suitable fission when products have greater total binding. The curve is a trend, not a complete stability rule.
Open the interactive experiment →Binding energy per nucleon
நடுத்தர அணுக்கருக்களில் ஒரு நியூக்ளியானுக்கான பிணைப்பு ஆற்றல் அதிகம். இலகு அணுக்கருக்களின் இணைவும் கனமானவற்றின் பிளவும்ஆற்றல் விடுவிக்கலாம்.
Key notes, relationships and model limits
Remember
Intermediate nuclei have high binding per nucleon. Light nuclei can release energy by fusion and heavy nuclei by suitable fission when products have greater total binding. The curve is a trend, not a complete stability rule.
Common trap
Binding per nucleon alone does not provide decay barriers or every isotope’s stability.
Model limits
Semi-empirical liquid-drop formula; curve uses approximate stable-Z choices. It is inaccurate for very light nuclei and ignores shell structure. Require1≤Z≤A.
What you will learn
Interpret nuclear-energy trends without assuming every reaction is allowed.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
This liquid-drop parameter set places Fe56 near8.85 MeV/nucleon.
Why this matters
The model connects binding energy per nucleon with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
Energy release is favored when products have?
- Less total binding
- More total binding
- The same masses by definition
Read the explanation
Greater binding means lower product rest energy.
Course connection: Class XII Chapter 13. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.