Nuclear structure and binding energy explorer
Explore nuclear notation, mass defect and binding energy per nucleon, then compare energy release in fission and fusion.
Learning goals
- Interpret nuclear structure, isotopes and Rutherford scattering.
- Apply conservation laws to nuclear equations, including beta decay.
- Use mass-energy equivalence, mass defect and binding energy.
- Relate binding energy per nucleon to fission, fusion, applications and hazards.
Iron-56: 26 protons and 30 neutrons. Mass defect 0.5285 u, binding energy 492.3 MeV, 8.79 MeV per nucleon.
- Make-up
- Z = 26, N = 30, A = 56
- Z ¹H atoms + N neutrons
- 56.463398 u
- Mass of the atom
- 55.934936 u
- Mass defect, Δm
- 0.528463 u
- Binding energy, EB = Δm c²
- 492.3 MeV
- EB per nucleon
- 8.790 MeV
- Mass before
- 5.030151 u
- Mass after
- 5.011268 u
- Mass lost, Δm
- 3.14 × 10⁻²⁹ kg
- Energy released, Q = Δm c²
- 17.59 MeV
- Q per nucleon of fuel
- 3.52 MeV
Try this
0 of 4 doneCompare iron-56 and nickel-62 at the top of the curve. (not done yet)
Nickel-62 (8.795 MeV per nucleon) just beats iron-56 (8.790 MeV). Nuclei near A = 60 are the most stable.
Pull a helium-4 nucleus apart. How much energy does it take? (not done yet)
28.3 MeV, which is Δm c². The same energy is released when two protons and two neutrons bind into helium-4.
Split uranium-235. Where do the fragments sit on the curve? (not done yet)
Both fragments are higher on the curve than uranium: they are more tightly bound, and the extra binding energy, about 180 MeV, is released.
Run D–T fusion too. Which releases more energy per nucleon of fuel? (not done yet)
Fusion: 17.6 MeV from 5 nucleons, 3.5 MeV each. Fission: about 180 MeV from 236 nucleons, under 1 MeV each.
You’ve tried every task.