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31.6 Binding Energy

Mass defect turned into the energy that holds a nucleus together, and the binding energy per nucleon curve that peaks near iron and drives fission and fusion.

College Physics 2e, 31.6 Binding Energy

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5 exercises

31.6 Exercise 3

2H^{2} \text{H} is a loosely bound isotope of hydrogen. Called deuterium or heavy hydrogen, it is stable but relatively rare—it is 0.015% of natural hydrogen. Note that deuterium has Z=NZ = N, which should tend to make it more tightly bound, but both are odd numbers. Calculate BE/ABE/ A, the binding energy per nucleon, for 2H^{2} \text{H} and compare it with the approximate value obtained from the graph in the figure.

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31.6 Exercise 5

209Bi^{\text{209}} \text{Bi} is the heaviest stable nuclide, and its BE/A\text{BE} / A is low compared with medium-mass nuclides. Calculate BE/ABE/ A, the binding energy per nucleon, for 209Bi^{\text{209}} \text{Bi} and compare it with the approximate value obtained from the graph in the figure.

2.5

31.6 Exercise 7

(a) Calculate BE/A\text{BE} / A for 12C^{\text{12}} \text{C}. Stable and relatively tightly bound, this nuclide is most of natural carbon. (b) Calculate BE/A\text{BE} / A for 14C^{\text{14}} \text{C}. Is the difference in BE/A\text{BE} / A between 12C^{\text{12}} \text{C} and 14C^{\text{14}} \text{C} significant? One is stable and common, and the other is unstable and rare.

2.5

31.6 Exercise 9

The purpose of this problem is to show in three ways that the binding energy of the electron in a hydrogen atom is negligible compared with the masses of the proton and electron. (a) Calculate the mass equivalent in u of the 13.6-eV binding energy of an electron in a hydrogen atom, and compare this with the mass of the hydrogen atom obtained from Appendix A. (b) Subtract the mass of the proton giv…

2.5

Unreasonable Results

A particle physicist discovers a neutral particle with a mass of 2.02733 u that he assumes is two neutrons bound together. (a) Find the binding energy. (b) What is unreasonable about this result? (c) What assumptions are unreasonable or inconsistent?

2.5

Adapted from College Physics © 2022 Rice University. Licensed under CC BY 4.0. Sources: College Physics 2e, College Physics for AP® Courses 2e. Imported at revision f98d7a7.