Semi-empirical mass formula and fission term

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SUMMARY

The semi-empirical mass formula indicates that the symmetry term is responsible for energy release during fission, particularly for β-stable nuclides heavier than 92Mo. The physical origin of this term is rooted in the Pauli exclusion principle, which prevents identical states from being occupied. Despite having a positive Q-value for fission, spontaneous fission does not occur in these nuclides due to the specific ratio of Z (atomic number) to A (mass number), which must satisfy Z²/A ≥ 49.

PREREQUISITES
  • Understanding of the semi-empirical mass formula
  • Knowledge of nuclear stability and fission processes
  • Familiarity with the Pauli exclusion principle
  • Basic grasp of nuclear physics terminology, including Q-value
NEXT STEPS
  • Research the implications of the semi-empirical mass formula on nuclear stability
  • Study the role of the symmetry term in nuclear reactions
  • Examine the conditions for spontaneous fission in various isotopes
  • Learn about the calculation and significance of Q-values in nuclear physics
USEFUL FOR

Students and educators in nuclear physics, researchers focusing on nuclear stability, and anyone interested in the principles of fission and energy release in heavy nuclides.

Ryomega
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Homework Statement



Which term in semi-empirical mass formula gives rise to the energy release in fission? What is the physical origin of this term? All β-stable nuclides heavier than 92Mo (Molybdenum) have a positive Q-value for fission; explain what prevents them decaying in this way.

Homework Equations



Semi-empirical mass formula:

Energy (Binding) = Volume term - Surface term - Coulomb repulsion term - a/symmetry term - pairing term

The Attempt at a Solution



I know that Z2/A ≥ 49 gives spontaneous fission. So that makes the symmetry term responsible for fission. The origin is Pauli exclusion principle where no same states can be occupied.

The rest of the question is complete gibberish to me. I'm not even sure WHCIH way is decaying for what WHAT way is decaying what?

Help.:cry:
 
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The Q value is the energy released during the reaction. A positive Q-value implies that the reaction may be possible.
However, if you look up the values of Z and A for 92Mo and put them into your formula: \frac{Z^2}{A}\geq49 you will find out why spontaneous fission cannot occur.
 

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